path: root/libhb/stream.c

/* $Id$

   This file is part of the HandBrake source code.
   Homepage: <http://handbrake.m0k.org/>.
   It may be used under the terms of the GNU General Public License. */

#include "hb.h"
#include "lang.h"
#include "a52dec/a52.h"

#include <string.h>

#define min(a, b) a < b ? a : b

typedef enum {
    hb_stream_type_unknown = 0,
    hb_stream_type_transport,
    hb_stream_type_program
} hb_stream_type_t;

#define kMaxNumberVideoPIDS 1
#define kMaxNumberAudioPIDS 15
#define kMaxNumberDecodeStreams (kMaxNumberVideoPIDS+kMaxNumberAudioPIDS)
#define kMaxNumberPMTStreams 32


struct hb_stream_s
{
    int     frames;             /* video frames so far */
    int     errors;             /* total errors so far */
    int     last_error_frame;   /* frame # at last error message */
    int     last_error_count;   /* # errors at last error message */

    int64_t ts_lastpcr;         /* the last pcr we found in the TS stream */
    int64_t ts_nextpcr;         /* the next pcr to put in a PS packet */

    uint8_t *ts_buf[kMaxNumberDecodeStreams];
    int     ts_pos[kMaxNumberDecodeStreams];
    int8_t  ts_foundfirst[kMaxNumberDecodeStreams];
    int8_t  ts_skipbad[kMaxNumberDecodeStreams];
    int8_t  ts_streamcont[kMaxNumberDecodeStreams];
    int8_t  ts_start[kMaxNumberDecodeStreams];

    uint8_t *fwrite_buf;        /* PS buffer (set by hb_ts_stream_decode) */
    uint8_t *fwrite_buf_orig;   /* PS buffer start (set by hb_ts_stream_decode) */

    /*
     * Stuff before this point is dynamic state updated as we read the
     * stream. Stuff after this point is stream description state that
     * we learn during the initial scan but cache so it can be
     * reused during the conversion read.
     */
    int16_t ts_video_pids[kMaxNumberVideoPIDS];
    int16_t ts_audio_pids[kMaxNumberAudioPIDS];

    uint8_t ts_number_video_pids;
    uint8_t ts_number_audio_pids;

    uint8_t ts_streamid[kMaxNumberDecodeStreams];
    uint8_t ts_video_stream_type[kMaxNumberDecodeStreams];
    uint8_t ts_audio_stream_type[kMaxNumberDecodeStreams];

    char    *path;
    FILE    *file_handle;
    hb_stream_type_t stream_type;
    int     opentype;

    struct {
        int lang_code;
        int flags;
        int rate;
        int bitrate;
    } a52_info[kMaxNumberAudioPIDS];

    struct
    {
        unsigned short program_number;
        unsigned short program_map_PID;
    } pat_info[kMaxNumberPMTStreams];
    int     ts_number_pat_entries;

    struct
    {
        int reading;
        unsigned char *tablebuf;
        unsigned int tablepos;
        unsigned char current_continuity_counter;

        int section_length;
        int program_number;
        unsigned int PCR_PID;
        int program_info_length;
        unsigned char *progam_info_descriptor_data;
        struct
        {
            unsigned char stream_type;
            unsigned short elementary_PID;
            unsigned short ES_info_length;
            unsigned char *es_info_descriptor_data;
        } pmt_stream_info[kMaxNumberPMTStreams];
    } pmt_info;
};

/***********************************************************************
 * Local prototypes
 **********************************************************************/
static void hb_stream_duration(hb_stream_t *stream, hb_title_t *inTitle);
static void hb_ts_stream_init(hb_stream_t *stream);
static void hb_ts_stream_find_pids(hb_stream_t *stream);
static int hb_ts_stream_decode(hb_stream_t *stream, uint8_t *obuf);
static void hb_ts_stream_reset(hb_stream_t *stream);
static hb_audio_t *hb_ts_stream_set_audio_id_and_codec(hb_stream_t *stream,
                                                       int aud_pid_index);
static void hb_ps_stream_find_audio_ids(hb_stream_t *stream, hb_title_t *title);
static off_t align_to_next_packet(FILE* f);

/*
 * streams have a bunch of state that's learned during the scan. We don't
 * want to throw away the state when scan does a close then relearn
 * everything when reader does an open. So we save the stream state on
 * the close following a scan and reuse it when 'reader' does an open.
 */
static hb_list_t *stream_state_list;

static hb_stream_t *hb_stream_lookup( const char *path )
{
    if ( stream_state_list == NULL )
        return NULL;

    hb_stream_t *ss;
    int i = 0;

    while ( ( ss = hb_list_item( stream_state_list, i++ ) ) != NULL )
    {
        if ( strcmp( path, ss->path ) == 0 )
        {
            break;
        }
    }
    return ss;
}

static void hb_stream_state_delete( hb_stream_t *ss )
{
    hb_list_rem( stream_state_list, ss );
    free( ss->path );
    free( ss );
}

static inline int check_ps_sync(const uint8_t *buf)
{
    // a legal MPEG program stream must start with a Pack header in the
    // first four bytes.
    return (buf[0] == 0x00) && (buf[1] == 0x00) &&
           (buf[2] == 0x01) && (buf[3] == 0xba);
}

static inline int check_ts_sync(const uint8_t *buf)
{
    // must have initial sync byte, no scrambling & a legal adaptation ctrl
    return (buf[0] == 0x47) && ((buf[3] >> 6) == 0) && ((buf[3] >> 4) > 0);
}

static inline int have_ts_sync(const uint8_t *buf)
{
    return check_ts_sync(&buf[0*188]) && check_ts_sync(&buf[1*188]) &&
           check_ts_sync(&buf[2*188]) && check_ts_sync(&buf[3*188]) &&
           check_ts_sync(&buf[4*188]) && check_ts_sync(&buf[5*188]) &&
           check_ts_sync(&buf[6*188]) && check_ts_sync(&buf[7*188]);
}

static int hb_stream_check_for_ts(const uint8_t *buf)
{
    // transport streams should have a sync byte every 188 bytes.
    // search the first KB of buf looking for at least 8 consecutive
    // correctly located sync patterns.
    int offset = 0;

    for ( offset = 0; offset < 1024; ++offset )
    {
        if ( have_ts_sync( &buf[offset]) )
            return 1;
    }
    return 0;
}

static int hb_stream_check_for_ps(const uint8_t *buf)
{
    // program streams should have a Pack header every 2048 bytes.
    // check that we have 4 of these.
    return check_ps_sync(&buf[0*2048]) && check_ps_sync(&buf[1*2048]) &&
           check_ps_sync(&buf[2*2048]) && check_ps_sync(&buf[3*2048]);
}

static int hb_stream_get_type(hb_stream_t *stream)
{
    uint8_t buf[2048*4];

    if ( fread(buf, 1, sizeof(buf), stream->file_handle) == sizeof(buf) )
    {
        if ( hb_stream_check_for_ts(buf) != 0 )
        {
            hb_log("file is MPEG Transport Stream");
            stream->stream_type = hb_stream_type_transport;
            hb_ts_stream_init(stream);
            return 1;
        }
        if ( hb_stream_check_for_ps(buf) != 0 )
        {
            hb_log("file is MPEG Program Stream");
            stream->stream_type = hb_stream_type_program;
            return 1;
        }
    }
    return 0;
}

static void hb_stream_delete_dynamic( hb_stream_t *d )
{
    if( d->file_handle )
    {
        fclose( d->file_handle );
		d->file_handle = NULL;
    }

	int i=0;

	for (i = 0; i < kMaxNumberDecodeStreams; i++)
	{
		if (d->ts_buf[i])
		{
			free(d->ts_buf[i]);
			d->ts_buf[i] = NULL;
		}
	}
}

static void hb_stream_delete( hb_stream_t *d )
{
    hb_stream_delete_dynamic( d );
    free( d->path );
    free( d );
}

/***********************************************************************
 * hb_stream_open
 ***********************************************************************
 *
 **********************************************************************/
hb_stream_t * hb_stream_open( char *path, int opentype )
{

    FILE *f = fopen( path, "r" );
    if ( f == NULL )
    {
        hb_log( "hb_stream_open: open %s failed", path );
        return NULL;
    }

    hb_stream_t *d = calloc( sizeof( hb_stream_t ), 1 );
    if ( d == NULL )
    {
        fclose( f );
        hb_log( "hb_stream_open: can't allocate space for %s stream state", path );
        return NULL;
    }

    /*
     * if we're opening the stream to read & convert, we need
     * the state we saved when we scanned the stream. if we're
     * opening the stream to scan it we want to rebuild the state
     * (even if we have saved state, the stream may have changed).
     */
    hb_stream_t *ss = hb_stream_lookup( path );
    if ( opentype == 1 )
    {
        /* opening to read - we must have saved state */
        if ( ss == NULL )
        {
            hb_log( "hb_stream_open: error: re-opening %s but no scan state", path );
            fclose( f );
            free( d );
            return NULL;
        }
        /*
         * copy the saved state since we might be encoding the same stream
         * multiple times.
         */
        memcpy( d, ss, sizeof(*d) );
        d->file_handle = f;
        d->opentype = opentype;
        d->path = strdup( path );

        if ( d->stream_type == hb_stream_type_transport )
        {
            int i = 0;
            for ( ; i < d->ts_number_video_pids + d->ts_number_audio_pids; i++)
            {
                d->ts_buf[i] = malloc( HB_DVD_READ_BUFFER_SIZE );
            }
            hb_stream_seek( d, 0. );
        }
        return d;
    }

    /*
     * opening for scan - delete any saved state then (re)scan the stream.
     * If it's something we can deal with (MPEG2 PS or TS) return a stream
     * reference structure & null otherwise.
     */

    if ( ss != NULL )
    {
        hb_stream_state_delete( ss );
    }
    d->file_handle = f;
    d->opentype = opentype;
    d->path = strdup( path );
    if (d->path != NULL &&  hb_stream_get_type( d ) != 0 )
    {
        return d;
    }
    fclose( d->file_handle );
    if (d->path)
    {
        free( d->path );
    }
    hb_log( "hb_stream_open: open %s failed", path );
    free( d );
    return NULL;
}

/***********************************************************************
 * hb_stream_close
 ***********************************************************************
 * Closes and frees everything
 **********************************************************************/
void hb_stream_close( hb_stream_t ** _d )
{
    hb_stream_t *stream = * _d;
    if ( stream->frames )
    {
        hb_log( "stream: %d good frames, %d errors (%.0f%%)", stream->frames,
                stream->errors, (double)stream->errors * 100. /
                (double)stream->frames );
    }
    /*
     * if the stream was opened for a scan, cache the result, otherwise delete
     * the state.
     */
    if ( stream->opentype == 0 )
    {
        hb_stream_delete_dynamic( stream );
        if ( stream_state_list == NULL )
        {
            stream_state_list = hb_list_init();
        }
        hb_list_add( stream_state_list, stream );
    }
    else
    {
        hb_stream_delete( stream );
    }
    *_d = NULL;
}

/* when the file was first opened we made entries for all the audio elementary
 * streams we found in it. Streams that were later found during the preview scan
 * now have an audio codec, type, rate, etc., associated with them. At the end
 * of the scan we delete all the audio entries that weren't found by the scan
 * or don't have a format we support. This routine deletes audio entry 'indx'
 * by copying all later entries down one slot. */
static void hb_stream_delete_audio_entry(hb_stream_t *stream, int indx)
{
    int i;

    for (i = indx+1; i < stream->ts_number_audio_pids; ++i)
    {
        stream->ts_audio_pids[indx] = stream->ts_audio_pids[i];
        stream->ts_audio_stream_type[1 + indx] = stream->ts_audio_stream_type[1+i];
        stream->ts_streamid[1 + indx] = stream->ts_streamid[1 + i];
        ++indx;
    }
    --stream->ts_number_audio_pids;
}

static int index_of_pid(int pid, hb_stream_t *stream)
{
    int i;

    if ( pid == stream->ts_video_pids[0] )
        return 0;

    for ( i = 0; i < stream->ts_number_audio_pids; ++i )
        if ( pid == stream->ts_audio_pids[i] )
            return i + 1;

    return -1;
}

/***********************************************************************
 * hb_ps_stream_title_scan
 ***********************************************************************
 *
 **********************************************************************/
hb_title_t * hb_stream_title_scan(hb_stream_t *stream)
{
    // 'Barebones Title'
    hb_title_t *aTitle = hb_title_init( stream->path, 0 );
    aTitle->index = 1;

	// Copy part of the stream path to the title name
	char *sep = strrchr(stream->path, '/');
	if (sep)
		strcpy(aTitle->name, sep+1);
	char *dot_term = strrchr(aTitle->name, '.');
	if (dot_term)
		*dot_term = '\0';

    // Height, width,  rate and aspect ratio information is filled in when the previews are built

    hb_stream_duration(stream, aTitle);

    // One Chapter
    hb_chapter_t * chapter;
    chapter = calloc( sizeof( hb_chapter_t ), 1 );
    chapter->index = 1;
    chapter->duration = aTitle->duration;
    chapter->hours = aTitle->hours;
    chapter->minutes = aTitle->minutes;
    chapter->seconds = aTitle->seconds;
    hb_list_add( aTitle->list_chapter, chapter );

    // Figure out how many audio streams we really have:
    // - For transport streams, for each PID listed in the PMT (whether
    //   or not it was an audio stream type) read the bitstream until we
    //   find an packet from that PID containing a PES header and see if
    //   the elementary stream is an audio type.
    // - For program streams read the first 4MB and take every unique
    //   audio stream we find.
	if (stream->stream_type == hb_stream_type_transport)
	{
        int i;

        for (i=0; i < stream->ts_number_audio_pids; i++)
        {
            hb_audio_t *audio = hb_ts_stream_set_audio_id_and_codec(stream, i);
            if (audio->config.in.codec)
                hb_list_add( aTitle->list_audio, audio );
            else
            {
                free(audio);
                hb_stream_delete_audio_entry(stream, i);
                --i;
            }
        }

        // add the PCR PID if we don't already have it
        if ( index_of_pid( stream->pmt_info.PCR_PID, stream ) < 0 )
        {
            stream->ts_audio_pids[stream->ts_number_audio_pids++] =
                stream->pmt_info.PCR_PID;
        }
	}
    else
    {
        hb_ps_stream_find_audio_ids(stream, aTitle);
    }

  return aTitle;
}

/*
 * scan the next MB of 'stream' to find the next start packet for
 * the Packetized Elementary Stream associated with TS PID 'pid'.
 */
static const uint8_t *hb_ts_stream_getPEStype(hb_stream_t *stream, uint32_t pid)
{
    static uint8_t buf[188];
    int npack = 100000; // max packets to read

    while (--npack >= 0)
    {
        if (fread(buf, 1, 188, stream->file_handle) != 188)
        {
            hb_log("hb_ts_stream_getPEStype: EOF while searching for PID 0x%x", pid);
            return 0;
        }
        if (buf[0] != 0x47)
        {
            hb_log("hb_ts_stream_getPEStype: lost sync while searching for PID 0x%x", pid);
            align_to_next_packet(stream->file_handle);
            continue;
        }

        /*
         * The PES header is only in TS packets with 'start' set so we check
         * that first then check for the right PID.
         */
        if ((buf[1] & 0x40) == 0 || (buf[1] & 0x1f) != (pid >> 8) ||
            buf[2] != (pid & 0xff))
        {
            // not a start packet or not the pid we want
            continue;
        }

        /* skip over the TS hdr to return a pointer to the PES hdr */
        int udata = 4;
        switch (buf[3] & 0x30)
        {
            case 0x00: // illegal
            case 0x20: // fill packet
                continue;

            case 0x30: // adaptation
                if (buf[4] > 182)
                {
                    hb_log("hb_ts_stream_getPEStype: invalid adaptation field length %d for PID 0x%x", buf[4], pid);
                    continue;
                }
                udata += buf[4] + 1;
                break;
        }
        return &buf[udata];
    }

    /* didn't find it */
    return 0;
}

static uint64_t hb_ps_stream_getVideoPTS(hb_stream_t *stream)
{
    hb_buffer_t *buf  = hb_buffer_init(HB_DVD_READ_BUFFER_SIZE);
    hb_list_t *list = hb_list_init();
    // how many blocks we read while searching for a video PES header
    int blksleft = 1024;
    uint64_t pts = 0;

    while (--blksleft >= 0 && hb_stream_read(stream, buf) == 1)
    {
        hb_buffer_t *es;

        // 'buf' contains an MPEG2 PACK - get a list of all it's elementary streams
        hb_demux_ps(buf, list);

        while ( ( es = hb_list_item( list, 0 ) ) )
        {
            hb_list_rem( list, es );
            if ( es->id == 0xe0 )
            {
                // this PES contains video - if there's a PTS we're done
                // hb_demux_ps left the PTS in buf_es->start.
                if ( es->start != ~0 )
                {
                    pts = es->start;
                    blksleft = 0;
                    break;
                }
            }
            hb_buffer_close( &es );
        }
    }
    hb_list_empty( &list );
    hb_buffer_close(&buf);
    return pts;
}

/***********************************************************************
 * hb_stream_duration
 ***********************************************************************
 *
 * Finding stream duration is difficult.  One issue is that the video file
 * may have chunks from several different program fragments (main feature,
 * commercials, station id, trailers, etc.) all with their own base pts
 * value.  We can't find the piece boundaries without reading the entire
 * file but if we compute a rate based on time stamps from two different
 * pieces the result will be meaningless.  The second issue is that the
 * data rate of compressed video normally varies by 5-10x over the length
 * of the video. This says that we want to compute the rate over relatively
 * long segments to get a representative average but long segments increase
 * the likelihood that we'll cross a piece boundary.
 *
 * What we do is take time stamp samples at several places in the file
 * (currently 16) then compute the average rate (i.e., ticks of video per
 * byte of the file) for all pairs of samples (N^2 rates computed for N
 * samples). Some of those rates will be absurd because the samples came
 * from different segments. Some will be way low or high because the
 * samples came from a low or high motion part of the segment. But given
 * that we're comparing *all* pairs the majority of the computed rates
 * should be near the overall average.  So we median filter the computed
 * rates to pick the most representative value.
 *
 **********************************************************************/
struct pts_pos {
    uint64_t pos;   /* file position of this PTS sample */
    uint64_t pts;   /* PTS from video stream */
};

#define NDURSAMPLES 16

// get one (position, timestamp) sampple from a transport or program
// stream.
static struct pts_pos hb_sample_pts(hb_stream_t *stream, uint64_t fpos)
{
    struct pts_pos pp = { 0, 0 };

    if ( stream->stream_type == hb_stream_type_program )
    {
        // round address down to nearest dvd sector start
        fpos &=~ ( HB_DVD_READ_BUFFER_SIZE - 1 );
        fseeko( stream->file_handle, fpos, SEEK_SET );
        pp.pts = hb_ps_stream_getVideoPTS( stream );
    }
    else
    {
        const uint8_t *buf;
        fseeko( stream->file_handle, fpos, SEEK_SET );
        align_to_next_packet( stream->file_handle );
        buf = hb_ts_stream_getPEStype( stream, stream->ts_video_pids[0] );
        if ( buf == NULL )
        {
            hb_log("hb_sample_pts: couldn't find video packet near %llu", fpos);
            return pp;
        }
        if ( ( buf[7] >> 7 ) != 1 )
        {
            hb_log("hb_sample_pts: no PTS in video packet near %llu", fpos);
            return pp;
        }
        pp.pts = ( ( (uint64_t)buf[9] >> 1 ) & 7 << 30 ) |
                 ( (uint64_t)buf[10] << 22 ) |
                 ( ( (uint64_t)buf[11] >> 1 ) << 15 ) |
                 ( (uint64_t)buf[12] << 7 ) |
                 ( (uint64_t)buf[13] >> 1 );
    }
    pp.pos = ftello(stream->file_handle);
    hb_log("hb_sample_pts: pts %lld at %llu", pp.pts, pp.pos );
    return pp;
}

static int dur_compare( const void *a, const void *b )
{
    const double *aval = a, *bval = b;
    return ( *aval < *bval ? -1 : ( *aval == *bval ? 0 : 1 ) );
}

// given an array of (position, time) samples, compute a max-likelihood
// estimate of the average rate by computing the rate between all pairs
// of samples then taking the median of those rates.
static double compute_stream_rate( struct pts_pos *pp, int n )
{
    int i, j;
    double rates[NDURSAMPLES * NDURSAMPLES / 2];
    double *rp = rates;

    // the following nested loops compute the rates between all pairs.
    *rp = 0;
    for ( i = 0; i < n-1; ++i )
    {
        // Bias the median filter by not including pairs that are "far"
        // from one another. This is to handle cases where the file is
        // made of roughly equal size pieces where a symmetric choice of
        // pairs results in having the same number of intra-piece &
        // inter-piece rate estimates. This would mean that the median
        // could easily fall in the inter-piece part of the data which
        // would give a bogus estimate. The 'ns' index creates an
        // asymmetry that favors locality.
        int ns = i + ( n >> 1 );
        if ( ns > n )
            ns = n;
        for ( j = i+1; j < ns; ++j )
        {
            if ( pp[j].pts != pp[i].pts && pp[j].pos > pp[i].pos )
            {
                *rp = ((double)( pp[j].pts - pp[i].pts )) /
                      ((double)( pp[j].pos - pp[i].pos ));
				++rp;
            }
        }
    }
    // now compute and return the median of all the (n*n/2) rates we computed
    // above.
    int nrates = rp - rates;
    qsort( rates, nrates, sizeof (rates[0] ), dur_compare );
    return rates[nrates >> 1];
}

static void hb_stream_duration(hb_stream_t *stream, hb_title_t *inTitle)
{
    struct pts_pos ptspos[NDURSAMPLES];
    struct pts_pos *pp = ptspos;
    int i;

    fseeko(stream->file_handle, 0, SEEK_END);
    uint64_t fsize = ftello(stream->file_handle);
    uint64_t fincr = fsize / NDURSAMPLES;
    uint64_t fpos = fincr / 2;
    for ( i = NDURSAMPLES; --i >= 0; fpos += fincr )
    {
        *pp++ = hb_sample_pts(stream, fpos);
    }
    uint64_t dur = compute_stream_rate( ptspos, pp - ptspos ) * (double)fsize;
    inTitle->duration = dur;
    dur /= 90000;
    inTitle->hours    = dur / 3600;
    inTitle->minutes  = ( dur % 3600 ) / 60;
    inTitle->seconds  = dur % 60;

    rewind(stream->file_handle);
}

/***********************************************************************
 * hb_stream_read
 ***********************************************************************
 *
 **********************************************************************/
int hb_stream_read( hb_stream_t * src_stream, hb_buffer_t * b )
{
    if ( src_stream->stream_type == hb_stream_type_program )
    {
        size_t amt_read = fread(b->data, HB_DVD_READ_BUFFER_SIZE, 1,
                                src_stream->file_handle);
        return (amt_read > 0);
    }
    return hb_ts_stream_decode( src_stream, b->data );
}

/***********************************************************************
 * hb_stream_seek
 ***********************************************************************
 *
 **********************************************************************/
int hb_stream_seek( hb_stream_t * src_stream, float f )
{
  off_t stream_size, cur_pos, new_pos;
  double pos_ratio = f;
  cur_pos = ftello(src_stream->file_handle);
  fseeko(src_stream->file_handle,0 ,SEEK_END);
  stream_size = ftello(src_stream->file_handle);
  new_pos = (off_t) ((double) (stream_size) * pos_ratio);
  new_pos &=~ (HB_DVD_READ_BUFFER_SIZE - 1);
  int r = fseeko(src_stream->file_handle, new_pos, SEEK_SET);

  if (r == -1)
  {
    fseeko(src_stream->file_handle, cur_pos, SEEK_SET);
    return 0;
  }

  if (src_stream->stream_type == hb_stream_type_transport)
  {
	// We need to drop the current decoder output and move
	// forwards to the next transport stream packet.
	hb_ts_stream_reset(src_stream);
  }

  return 1;
}

static void set_audio_description( hb_audio_t *audio, iso639_lang_t *lang )
{
    /* XXX
     * This is a duplicate of code in dvd.c - it should get factored out
     * into a common routine. We probably should only be putting the lang
     * code or a lang pointer into the audio config & let the common description
     * formatting routine in scan.c do all the stuff below.
     */
    snprintf( audio->config.lang.description,
              sizeof( audio->config.lang.description ), "%s (%s)",
              strlen(lang->native_name) ? lang->native_name : lang->eng_name,
              audio->config.in.codec == HB_ACODEC_AC3 ? "AC3" :
                  audio->config.in.codec == HB_ACODEC_DCA ? "DTS" :
                      audio->config.in.codec == HB_ACODEC_MPGA ? "MPEG" : "LPCM" );
    snprintf( audio->config.lang.simple, sizeof( audio->config.lang.simple ), "%s",
              strlen(lang->native_name) ? lang->native_name : lang->eng_name );
    snprintf( audio->config.lang.iso639_2, sizeof( audio->config.lang.iso639_2 ),
              "%s", lang->iso639_2);
}

static hb_audio_t *hb_ts_stream_set_audio_id_and_codec(hb_stream_t *stream,
                                                       int aud_pid_index)
{
    off_t cur_pos = ftello(stream->file_handle);
    hb_audio_t *audio = calloc( sizeof( hb_audio_t ), 1 );
    const uint8_t *buf;

    fseeko(stream->file_handle, 0, SEEK_SET);
    align_to_next_packet(stream->file_handle);
    buf = hb_ts_stream_getPEStype(stream, stream->ts_audio_pids[aud_pid_index]);

    /* check that we found a PES header */
    if (buf && buf[0] == 0x00 && buf[1] == 0x00 && buf[2] == 0x01)
    {
        if (buf[3] == 0xbd)
        {
            audio->id = 0x80bd | (aud_pid_index << 8);
            audio->config.in.codec = HB_ACODEC_AC3;
            hb_log("transport stream pid 0x%x (type 0x%x) is AC-3 audio id 0x%x",
                   stream->ts_audio_pids[aud_pid_index],
                   stream->ts_audio_stream_type[1 + aud_pid_index],
                   audio->id);
            stream->ts_audio_stream_type[1 + aud_pid_index] = 0x81;
            stream->ts_streamid[1 + aud_pid_index] = buf[3];
        }
        else if ((buf[3] & 0xe0) == 0xc0)
        {
            audio->id = buf[3] | aud_pid_index;
            audio->config.in.codec = HB_ACODEC_MPGA;
            hb_log("transport stream pid 0x%x (type 0x%x) is MPEG audio id 0x%x",
                   stream->ts_audio_pids[aud_pid_index],
                   stream->ts_audio_stream_type[1 + aud_pid_index],
                   audio->id);
            stream->ts_audio_stream_type[1 + aud_pid_index] = 0x03;
            stream->ts_streamid[1 + aud_pid_index] = buf[3];
        }
    }
    fseeko(stream->file_handle, cur_pos, SEEK_SET);
    if ( audio->config.in.codec )
    {
		set_audio_description( audio,
                  lang_for_code( stream->a52_info[aud_pid_index].lang_code ) );
    }
    else
    {
        hb_log("transport stream pid 0x%x (type 0x%x) isn't audio",
                stream->ts_audio_pids[aud_pid_index],
                stream->ts_audio_stream_type[1 + aud_pid_index]);
	}
    return audio;
}

static void add_audio_to_title(hb_title_t *title, int id)
{
    hb_audio_t *audio = calloc( sizeof( hb_audio_t ), 1 );

    audio->id = id;
    switch ( id >> 12 )
    {
        case 0x0:
            audio->config.in.codec = HB_ACODEC_MPGA;
            hb_log("add_audio_to_title: added MPEG audio stream 0x%x", id);
            break;
        case 0x2:
            // type 2 is a DVD subtitle stream - just ignore it */
            free( audio );
            return;
        case 0x8:
            audio->config.in.codec = HB_ACODEC_AC3;
            hb_log("add_audio_to_title: added AC3 audio stream 0x%x", id);
            break;
        case 0xa:
            audio->config.in.codec = HB_ACODEC_LPCM;
            hb_log("add_audio_to_title: added LPCM audio stream 0x%x", id);
            break;
        default:
            hb_log("add_audio_to_title: unknown audio stream type 0x%x", id);
            free( audio );
            return;

    }
    set_audio_description( audio, lang_for_code( 0 ) );
    hb_list_add( title->list_audio, audio );
}

static void hb_ps_stream_find_audio_ids(hb_stream_t *stream, hb_title_t *title)
{
    off_t cur_pos = ftello(stream->file_handle);
    hb_buffer_t *buf  = hb_buffer_init(HB_DVD_READ_BUFFER_SIZE);
    hb_list_t *list = hb_list_init();
    // how many blocks we read while searching for audio streams
    int blksleft = 4096;
    // there can be at most 16 unique streams in an MPEG PS (8 in a DVD)
    // so we use a bitmap to keep track of the ones we've already seen.
    // Bit 'i' of smap is set if we've already added the audio for
    // audio substream id 'i' to the title's audio list.
    uint32_t smap = 0;

    // start looking 20% into the file since there's occasionally no
    // audio at the beginning (particularly for vobs).
    hb_stream_seek(stream, 0.2f);

    while (--blksleft >= 0 && hb_stream_read(stream, buf) == 1)
    {
        hb_buffer_t *es;

        // 'buf' contains an MPEG2 PACK - get a list of all it's elementary streams
        hb_demux_ps(buf, list);

        while ( ( es = hb_list_item( list, 0 ) ) )
        {
            hb_list_rem( list, es );
            if ( (es->id & 0xff) == 0xbd || (es->id & 0xe0) == 0xc0 )
            {
                // this PES contains some kind of audio - get the substream id
                // and check if we've seen it already.
                int ssid = (es->id > 0xff ? es->id >> 8 : es->id) & 0xf;
                if ( (smap & (1 << ssid)) == 0 )
                {
                    // we haven't seen this stream before - add it to the
                    // title's list of audio streams.
                    smap |= (1 << ssid);
                    add_audio_to_title(title, es->id);
                }
            }
            hb_buffer_close( &es );
        }
    }
    hb_list_empty( &list );
    hb_buffer_close(&buf);
    fseeko(stream->file_handle, cur_pos, SEEK_SET);
}

/***********************************************************************
 * hb_ts_stream_init
 ***********************************************************************
 *
 **********************************************************************/

static void hb_ts_stream_init(hb_stream_t *stream)
{
	int i;

	for (i=0; i < kMaxNumberDecodeStreams; i++)
	{
		stream->ts_streamcont[i] = -1;
	}
	stream->ts_video_pids[0] = -1;
    for ( i = 0; i < stream->ts_number_audio_pids; i++ )
    {
        stream-> ts_audio_pids[i] = -1;
    }

	// Find the audio and video pids in the stream
	hb_ts_stream_find_pids(stream);

    stream->ts_streamid[0] = 0xE0;		// stream 0 must be video

	for (i = 0; i < stream->ts_number_video_pids + stream->ts_number_audio_pids; i++)
	{
        // demuxing buffer for TS to PS conversion
		stream->ts_buf[i] = malloc( HB_DVD_READ_BUFFER_SIZE );
	}
}

// ------------------------------------------------------------------------------------

static off_t align_to_next_packet(FILE* f)
{
	unsigned char buf[188*20];

	off_t start = ftello(f);
	off_t pos = 0;

	if (fread(buf, 188*20, 1, f) == 1)
	{
		int found = 0;
		while (!found && (pos < 188))
		{
			found = 1;
			int i = 0;
			for (i = 0; i < 188*20; i += 188)
			{
				unsigned char c = buf[pos+i];
				// Check sync byte
				if ((c != 0x47) && (c != 0x72) && (c != 0x29))
				{
					// this offset failed, try next
					found = 0;
					pos++;
					break;
				}
			}
		}
	}

	if (pos == 188)
		pos = 0;		// failed to find anything!!!!!?

    fseeko(f, start+pos, SEEK_SET);

	return pos;
}


typedef struct {
    uint8_t *buf;
    uint32_t val;
    int pos;
} bitbuf_t;

static const unsigned int bitmask[] = {
	0x0,0x1,0x3,0x7,0xf,0x1f,0x3f,0x7f,0xff,
	0x1ff,0x3ff,0x7ff,0xfff,0x1fff,0x3fff,0x7fff,0xffff,
	0x1ffff,0x3ffff,0x7ffff,0xfffff,0x1fffff,0x3fffff,0x7fffff,0xffffff,
	0x1ffffff,0x3ffffff,0x7ffffff,0xfffffff,0x1fffffff,0x3fffffff,0x7fffffff,0xffffffff};

static inline void set_buf(bitbuf_t *bb, uint8_t* buf, int bufsize, int clear)
{
	bb->pos = 0;
	bb->buf = buf;
	bb->val = (bb->buf[0] << 24) | (bb->buf[1] << 16) |
              (bb->buf[2] << 8) | bb->buf[3];
	if (clear)
		memset(bb->buf, 0, bufsize);
}

static inline int buf_size(bitbuf_t *bb)
{
	return bb->pos >> 3;
}

static inline unsigned int get_bits(bitbuf_t *bb, int bits)
{
	unsigned int val;
	int left = 32 - (bb->pos & 31);

	if (bits < left)
	{
		val = (bb->val >> (left - bits)) & bitmask[bits];
		bb->pos += bits;
	}
	else
	{
		val = (bb->val & bitmask[left]) << (bits - left);
		bb->pos += left;
		bits -= left;

		int pos = bb->pos >> 3;
		bb->val = (bb->buf[pos] << 24) | (bb->buf[pos + 1] << 16) | (bb->buf[pos + 2] << 8) | bb->buf[pos + 3];

		if (bits > 0)
		{
			val |= (bb->val >> (32 - bits)) & bitmask[bits];
			bb->pos += bits;
		}
	}

	return val;
}

// extract what useful information we can from the elementary stream
// descriptor list at 'dp' and add it to the stream at 'esindx'.
// Descriptors with info we don't currently use are ignored.
// The descriptor list & descriptor item formats are defined in
// ISO 13818-1 (2000E) section 2.6 (pg. 62).
static void decode_element_descriptors(hb_stream_t* stream, int esindx,
                                       const uint8_t *dp, uint8_t dlen)
{
    const uint8_t *ep = dp + dlen;

    while (dp < ep)
    {
        switch (dp[0])
        {
            case 10:    // ISO_639_language descriptor
                stream->a52_info[esindx].lang_code = lang_to_code(lang_for_code2((const char *)&dp[2]));
                break;

            default:
                break;
        }
        dp += dp[1] + 2;
    }
}

/*
 * Get the name of the stream from the type - thanks to VLC for this.
 */
static const char *get_stream_name (unsigned char stream_type)
{
    switch( stream_type )
    {
    case 0x01:  /* MPEG-1 video */
    case 0x02:  /* MPEG-2 video */
    case 0x80:  /* MPEG-2 MOTO video */
        return("MPEG 1/2 Video");
        break;
    case 0x03:  /* MPEG-1 audio */
    case 0x04:  /* MPEG-2 audio */
        return("MPEG Audio");
        break;
    case 0x11:  /* MPEG4 (audio) */
    case 0x0f:  /* ISO/IEC 13818-7 Audio with ADTS transport syntax */
        return("MPEG-4 Audio");
        break;
    case 0x10:  /* MPEG4 (video) */
        return("MPEG-4 Video");
        break;
    case 0x1B:  /* H264 <- check transport syntax/needed descriptor */
        return("H.264 Video");
        break;
        
    case 0x81:  /* A52 (audio) */
        return("A52/AC-3 Audio");
        break;
    case 0x82:  /* DVD_SPU (sub) */
        return("Subtitle");
        break;
    case 0x83:  /* LPCM (audio) */
        return("LPCM Audio");
        break;
    case 0x84:  /* SDDS (audio) */
        return("SDDS Audio");
        break;
    case 0x85:  /* DTS (audio) */
        return("DTS Audio");
        break;
        
    case 0x91:  /* A52 vls (audio) */
        return("A52b/AC-3 Audio");
        break;
    case 0x92:  /* DVD_SPU vls (sub) */
        return("Subtitle");
        break;
        
    case 0x94:  /* SDDS (audio) */
        return("SDDS Audio");
        break;
        
    case 0xa0:  /* MSCODEC vlc (video) (fixed later) */
        return("MSCODEC Video");
        break;
        
    case 0x06:  /* PES_PRIVATE  (fixed later) */
    case 0x12:  /* MPEG-4 generic (sub/scene/...) (fixed later) */
    case 0xEA:  /* Privately managed ES (VC-1) (fixed later */
    default:
        return("Other");
        break;
    }
}

int decode_program_map(hb_stream_t* stream)
{
    bitbuf_t bb;
	set_buf(&bb, stream->pmt_info.tablebuf, stream->pmt_info.tablepos, 0);

    get_bits(&bb, 8);  // table_id
    get_bits(&bb, 4);
    unsigned int section_length = get_bits(&bb, 12);
    stream->pmt_info.section_length = section_length;

    unsigned int program_number = get_bits(&bb, 16);
    stream->pmt_info.program_number = program_number;
    get_bits(&bb, 2);
    get_bits(&bb, 5);  // version_number
    get_bits(&bb, 1);
    get_bits(&bb, 8);  // section_number
    get_bits(&bb, 8);  // last_section_number
    get_bits(&bb, 3);
    unsigned int PCR_PID = get_bits(&bb, 13);
    stream->pmt_info.PCR_PID = PCR_PID;
    get_bits(&bb, 4);
    unsigned int program_info_length = get_bits(&bb, 12);
    stream->pmt_info.program_info_length = program_info_length;

	int i=0;
	unsigned char *descriptor_buf = (unsigned char *) malloc(program_info_length);
	for (i = 0; i < program_info_length; i++)
	{
	  descriptor_buf[i] = get_bits(&bb, 8);
	}

	int cur_pos =  9 /* data after the section length field*/ + program_info_length;
	int done_reading_stream_types = 0;
	while (!done_reading_stream_types)
	{
	  unsigned char stream_type = get_bits(&bb, 8);
		  get_bits(&bb, 3);
	  unsigned int elementary_PID = get_bits(&bb, 13);
		  get_bits(&bb, 4);
	  unsigned int ES_info_length = get_bits(&bb, 12);

	  int i=0;
	  unsigned char *ES_info_buf = (unsigned char *) malloc(ES_info_length);
	  for (i=0; i < ES_info_length; i++)
	  {
		ES_info_buf[i] = get_bits(&bb, 8);
	  }


	  if (stream_type == 0x02 || stream_type == 0x10 || stream_type == 0x1B)
	  {
              /* MPEG-2/MPEG-4/H.264 */
              if (stream->ts_number_video_pids <= kMaxNumberVideoPIDS)
		  stream->ts_number_video_pids++;
              stream->ts_video_pids[stream->ts_number_video_pids-1] = elementary_PID;
              stream->ts_video_stream_type[stream->ts_number_video_pids-1] = stream_type;
	  }
          else
          {
              // Defined audio stream types are 0x81 for AC-3/A52 audio and 0x03
              // for mpeg audio. But content producers seem to use other
              // values (0x04 and 0x06 have both been observed) so at this point
              // we say everything that isn't a video pid is audio then at the end
              // of hb_stream_title_scan we'll figure out which are really audio
              // by looking at the PES headers.
              i = stream->ts_number_audio_pids;
              if (i < kMaxNumberAudioPIDS)
                  stream->ts_number_audio_pids++;
              stream->ts_audio_pids[i] = elementary_PID;
              stream->ts_audio_stream_type[1 + i] = stream_type;
              
              if (ES_info_length > 0)
              {
                  decode_element_descriptors(stream, i, ES_info_buf, ES_info_length);
              }
	  }
          
	  cur_pos += 5 /* stream header */ + ES_info_length;

	  free(ES_info_buf);

	  if (cur_pos >= section_length - 4 /* stop before the CRC */)
		done_reading_stream_types = 1;
	}

	free(descriptor_buf);
	return 1;
}

// ------------------------------------------------------------------------------------

int build_program_map(unsigned char *buf, hb_stream_t *stream)
{
    // Get adaption header info
    int adapt_len = 0;
    int adaption = (buf[3] & 0x30) >> 4;
    if (adaption == 0)
            return 0;
    else if (adaption == 0x2)
            adapt_len = 184;
    else if (adaption == 0x3)
            adapt_len = buf[4] + 1;
    if (adapt_len > 184)
            return 0;

    // Get payload start indicator
    int start;
    start = (buf[1] & 0x40) != 0;

    // Get pointer length - only valid in packets with a start flag
    int pointer_len = 0;
	if (start && stream->pmt_info.reading)
	{
		// We just finished a bunch of packets - parse the program map details
		int decode_ok = 0;
		if (stream->pmt_info.tablebuf[0] == 0x02)
			decode_ok = decode_program_map(stream);
		free(stream->pmt_info.tablebuf);
		stream->pmt_info.tablebuf = NULL;
		stream->pmt_info.tablepos = 0;
        stream->pmt_info.reading = 0;
        if (decode_ok)
			return decode_ok;
	}

	if (start)
	{
		pointer_len = buf[4 + adapt_len] + 1;
		stream->pmt_info.tablepos = 0;
	}
	// Get Continuity Counter
	int continuity_counter = buf[3] & 0x0f;
	if (!start && (stream->pmt_info.current_continuity_counter + 1 != continuity_counter))
	{
		hb_log("build_program_map - Continuity Counter %d out of sequence - expected %d", continuity_counter, stream->pmt_info.current_continuity_counter+1);
		return 0;
	}
	stream->pmt_info.current_continuity_counter = continuity_counter;
	stream->pmt_info.reading |= start;

    // Add the payload for this packet to the current buffer
	int amount_to_copy = 184 - adapt_len - pointer_len;
    if (stream->pmt_info.reading && (amount_to_copy > 0))
    {
			stream->pmt_info.tablebuf = realloc(stream->pmt_info.tablebuf, stream->pmt_info.tablepos + amount_to_copy);

            memcpy(stream->pmt_info.tablebuf + stream->pmt_info.tablepos, buf + 4 + adapt_len + pointer_len, amount_to_copy);
            stream->pmt_info.tablepos += amount_to_copy;
    }

    return 0;
}

int decode_PAT(unsigned char *buf, hb_stream_t *stream)
{
    unsigned char tablebuf[1024];
    unsigned int tablepos = 0;

    int reading = 0;


    // Get adaption header info
    int adapt_len = 0;
    int adaption = (buf[3] & 0x30) >> 4;
    if (adaption == 0)
            return 0;
    else if (adaption == 0x2)
            adapt_len = 184;
    else if (adaption == 0x3)
            adapt_len = buf[4] + 1;
    if (adapt_len > 184)
            return 0;

    // Get pointer length
    int pointer_len = buf[4 + adapt_len] + 1;

    // Get payload start indicator
    int start;
    start = (buf[1] & 0x40) != 0;

    if (start)
            reading = 1;

    // Add the payload for this packet to the current buffer
    if (reading && (184 - adapt_len) > 0)
    {
            if (tablepos + 184 - adapt_len - pointer_len > 1024)
            {
                    hb_log("decode_PAT - Bad program section length (> 1024)");
                    return 0;
            }
            memcpy(tablebuf + tablepos, buf + 4 + adapt_len + pointer_len, 184 - adapt_len - pointer_len);
            tablepos += 184 - adapt_len - pointer_len;
    }

    if (start && reading)
    {
            memcpy(tablebuf + tablepos, buf + 4 + adapt_len + 1, pointer_len - 1);


            unsigned int pos = 0;
            //while (pos < tablepos)
            {
                    bitbuf_t bb;
                    set_buf(&bb, tablebuf + pos, tablepos - pos, 0);

                    unsigned char section_id	= get_bits(&bb, 8);
                    get_bits(&bb, 4);
                    unsigned int section_len	= get_bits(&bb, 12);
                    get_bits(&bb, 16); // transport_id
                    get_bits(&bb, 2);
                    get_bits(&bb, 5);  // version_num
                    get_bits(&bb, 1);  // current_next
                    get_bits(&bb, 8);  // section_num
                    get_bits(&bb, 8);  // last_section

                    switch (section_id)
                    {
                      case 0x00:
                        {
                          // Program Association Section
                          section_len -= 5;    // Already read transport stream ID, version num, section num, and last section num
                          section_len -= 4;   // Ignore the CRC
                          int curr_pos = 0;
						  stream->ts_number_pat_entries = 0;
                          while ((curr_pos < section_len) && (stream->ts_number_pat_entries < kMaxNumberPMTStreams))
                          {
                            unsigned int pkt_program_num = get_bits(&bb, 16);
							stream->pat_info[stream->ts_number_pat_entries].program_number = pkt_program_num;

                            get_bits(&bb, 3);  // Reserved
                            if (pkt_program_num == 0)
                            {
                              get_bits(&bb, 13); // pkt_network_id
                            }
                            else
                            {
                              unsigned int pkt_program_map_PID = get_bits(&bb, 13);
                                stream->pat_info[stream->ts_number_pat_entries].program_map_PID = pkt_program_map_PID;
                            }
                            curr_pos += 4;
							stream->ts_number_pat_entries++;
                          }
                        }
                        break;
                      case 0xC7:
                            {
                                    break;
                            }
                      case 0xC8:
                            {
                                    break;
                            }
                    }

                    pos += 3 + section_len;
            }

            tablepos = 0;
    }
    return 1;
}

static void hb_ts_stream_find_pids(hb_stream_t *stream)
{
	unsigned char buf[188];

	// align to first packet
	align_to_next_packet(stream->file_handle);

	// Read the Transport Stream Packets (188 bytes each) looking at first for PID 0 (the PAT PID), then decode that
	// to find the program map PID and then decode that to get the list of audio and video PIDs

	int bytesReadInPacket = 0;
	for (;;)
	{
		// Try to read packet..
		int bytesRead;
		if ((bytesRead = fread(buf+bytesReadInPacket, 1, 188-bytesReadInPacket, stream->file_handle)) != 188-bytesReadInPacket)
		{
			if (bytesRead < 0)
				bytesRead = 0;
			bytesReadInPacket += bytesRead;

			hb_log("hb_ts_stream_find_pids - end of file");
			break;
		}
		else
		{
			bytesReadInPacket = 0;
		}

		// Check sync byte
		if ((buf[0] != 0x47) && (buf[0] != 0x72) && (buf[0] != 0x29))
		{
            off_t pos = ftello(stream->file_handle) - 188;
            off_t pos2 = align_to_next_packet(stream->file_handle);
            if ( pos2 == 0 )
            {
                hb_log( "hb_ts_stream_find_pids: eof while re-establishing sync @ %lld",
                        pos );
                break;
            }
            hb_log("hb_ts_stream_decode: sync lost @%lld, regained after %lld bytes",
                    pos, pos2 );
			continue;
		}

		// Get pid
		int pid = (((buf[1] & 0x1F) << 8) | buf[2]) & 0x1FFF;

        if ((pid == 0x0000) && (stream->ts_number_pat_entries == 0))
		{
		  decode_PAT(buf, stream);
		  continue;
		}

		int pat_index = 0;
		for (pat_index = 0; pat_index < stream->ts_number_pat_entries; pat_index++)
		{
			// There are some streams where the PAT table has multiple entries as if their are
			// multiple programs in the same transport stream, and yet there's actually only one
			// program really in the stream. This seems to be true for transport streams that
			// originate in the HDHomeRun but have been output by EyeTV's export utility. What I think
			// is happening is that the HDHomeRun is sending the entire transport stream as broadcast,
			// but the EyeTV is only recording a single (selected) program number and not rewriting the
			// PAT info on export to match what's actually on the stream.
			// Until we have a way of handling multiple programs per transport stream elegantly we'll match
			// on the first pat entry for which we find a matching program map PID.  The ideal solution would
			// be to build a title choice popup from the PAT program number details and then select from
			// their - but right now the API's not capable of that.
			if (pid == stream->pat_info[pat_index].program_map_PID)
			{
			  if (build_program_map(buf, stream) > 0)
				break;
			}
		}
		// Keep going  until we have a complete set of PIDs
		if ((stream->ts_number_video_pids > 0) && (stream->ts_number_audio_pids > 0))
		  break;
	}

	hb_log("hb_ts_stream_find_pids - found the following PIDS");
	hb_log("    Video PIDS : ");
	int i=0;
	for (i=0; i < stream->ts_number_video_pids; i++)
	{
		hb_log("      0x%x (%d) [Type %s (0x%x)]", 
                       stream->ts_video_pids[i], stream->ts_video_pids[i],
                       get_stream_name(stream->ts_video_stream_type[i]),
                       stream->ts_video_stream_type[i]);
	}
	hb_log("    Audio PIDS : ");
	for (i = 0; i < stream->ts_number_audio_pids; i++)
	{
		hb_log("      0x%x (%d) [Type %s (0x%x)]", 
                       stream->ts_audio_pids[i], stream->ts_audio_pids[i],
                       get_stream_name(stream->ts_audio_stream_type[i]),
                       stream->ts_audio_stream_type[i] );
	}
 }


static void fwrite64( hb_stream_t *stream, void *buf, int size )
{
    if ( (stream->fwrite_buf - stream->fwrite_buf_orig) + size > 2048 )
    {
        hb_log( "steam fwrite64 buffer overflow - writing %d with %d already",
                size, stream->fwrite_buf - stream->fwrite_buf_orig );
        return;
    }
    memcpy( stream->fwrite_buf, buf, size );
    stream->fwrite_buf += size;
}

static void write_pack(hb_stream_t* stream, uint64_t time, int stuffing)
{
	uint8_t buf[24];

    buf[0] = 0x00;      // pack id
    buf[1] = 0x00;
    buf[2] = 0x01;
    buf[3] = 0xba;

    buf[4] = 0x44 |     // SCR
             ( ( ( time >> 30 ) & 7 ) << 3 ) |
             ( ( time >> 28 ) & 3 );
    buf[5] = time >> 20;
    buf[6] = 0x04 |
             ( ( ( time >> 15 ) & 0x1f ) << 3 ) |
             ( ( time >> 13 ) & 3 );
    buf[7] = time >> 5;
    buf[8] = 0x04 | ( time << 3 );

    buf[9] = 0x01;      // SCR extension

    buf[10] = 384000 >> (22 - 8);     // program mux rate
    buf[11] = (uint8_t)( 384000 >> (22 - 16) );
    buf[12] = (uint8_t)( 384000 << 2 ) | 0x03;

    buf[13] = 0xf8 | stuffing;

    int i;
    for (i = 0; i < stuffing; ++i )
        buf[14+i] = 0xff;

	fwrite64(stream, buf, 14 + stuffing );
}

static void pad_buffer(hb_stream_t* stream, int pad)
{
	pad -= 6;

	uint8_t buf[6];
	buf[0] = 0;
    buf[1] = 0;
    buf[2] = 0;
    buf[3] = 0xbe;
	buf[4] = pad >> 8;
    buf[5] = pad;

	fwrite64(stream, buf, 6);

	buf[0] = 0xff;
    while ( --pad >= 0 )
    {
		fwrite64(stream, buf, 1);
	}
}

static void make_pes_header(hb_stream_t* stream, int len, uint8_t streamid)
{
	uint8_t buf[9];

    memset(buf, 0, sizeof(buf) );
    buf[2] = 1;
    buf[3] = streamid;
    buf[4] = ( len + 3 ) >> 8;
    buf[5] = len + 3;
    buf[6] = 0x88;

    fwrite64(stream, buf, 9);
}

static void generate_output_data(hb_stream_t *stream, int curstream)
{
    uint8_t *tdat = stream->ts_buf[curstream];
    int len;

    // we always ship a PACK header plus all the data in our demux buf.
    // AC3 audio also always needs it substream header.
    len = 14 + stream->ts_pos[curstream];
    if ( stream->ts_audio_stream_type[curstream] == 0x81)
    {
        len += 4;
    }

    if ( ! stream->ts_start[curstream] )
    {
        // we're in the middle of a chunk of PES data - we need to add
        // a 'continuation' PES header after the PACK header.
        len += 9;
    }

    // Write out pack header
    // If we don't have 2048 bytes we need to pad to 2048. We can
    // add a padding frame after our data but we need at least 7
    // bytes of space to do it (6 bytes of header & 1 of pad). If
    // we have fewer than 7 bytes left we need to fill the excess
    // space with stuffing bytes added to the pack header.
    int stuffing = 0;
    if ( len > HB_DVD_READ_BUFFER_SIZE )
    {
        hb_log( "stream ts length botch %d", len );
    }
    if ( HB_DVD_READ_BUFFER_SIZE - len < 8)
    {
        stuffing = HB_DVD_READ_BUFFER_SIZE - len;
    }
    write_pack(stream, stream->ts_nextpcr, stuffing );
    stream->ts_nextpcr += 10;

    if ( stream->ts_start[curstream] )
    {
        // Start frames already have a PES header but we have modify it
        // to map from TS PID to PS stream id. Also, if the stream is AC3
        // audio we have to insert an AC3 stream header between the end of
        // the PES header and the start of the stream data.

        stream->ts_start[curstream] = 0;
        tdat[3] = stream->ts_streamid[curstream];

        uint16_t plen = stream->ts_pos[curstream] - 6;
        if ( stream->ts_audio_stream_type[curstream] == 0x81)
        {
            // We have to add an AC3 header in front of the data. Add its
            // size to the PES packet length.
            plen += 4;
            tdat[4] = plen >> 8;
            tdat[5] = plen;

            // Write out the PES header
            int hdrsize = 9 + tdat[8];
            fwrite64(stream, tdat, hdrsize);

            // add a four byte DVD ac3 stream header
            uint8_t ac3_substream_id[4];
            int ssid = (curstream - stream->ts_number_video_pids) & 0xf;
            ac3_substream_id[0] = 0x80 | ssid;  // substream id
            ac3_substream_id[1] = 0x01;         // number of sync words
            ac3_substream_id[2] = 0x00;         // first offset (16 bits)
            ac3_substream_id[3] = 0x02;
            fwrite64(stream, ac3_substream_id, 4);

            // add the rest of the data
            fwrite64(stream, tdat + hdrsize, stream->ts_pos[curstream] - hdrsize);
        }
        else
        {
            // not audio - don't need to modify the stream so write what we've got
            tdat[4] = plen >> 8;
            tdat[5] = plen;
            fwrite64( stream,  tdat, stream->ts_pos[curstream] );
        }
    }
    else
    {
        // data without a PES start header needs a simple 'continuation'
        // PES header. AC3 audio also needs its substream header.
        if ( stream->ts_audio_stream_type[curstream] != 0x81)
        {
            make_pes_header(stream, stream->ts_pos[curstream],
                            stream->ts_streamid[curstream]);
        }
        else
        {
            make_pes_header(stream, stream->ts_pos[curstream] + 4,
                            stream->ts_streamid[curstream]);

            // add a four byte DVD ac3 stream header
            uint8_t ac3_substream_id[4];
            int ssid = (curstream - stream->ts_number_video_pids) & 0xf;
            ac3_substream_id[0] = 0x80 | ssid;  // substream id
            ac3_substream_id[1] = 0x01;         // number of sync words
            ac3_substream_id[2] = 0x00;         // first offset (16 bits)
            ac3_substream_id[3] = 0x02;
            fwrite64(stream, ac3_substream_id, 4);
        }
        fwrite64( stream, tdat, stream->ts_pos[curstream] );
    }

    // Write padding
    int left = HB_DVD_READ_BUFFER_SIZE - len;
    if ( left >= 8 )
    {
        pad_buffer(stream, left);
    }

    stream->ts_pos[curstream] = 0;
}

static void ts_warn_helper( hb_stream_t *stream, char *log, va_list args )
{
    // limit error printing to at most one per minute of video (at 30fps)
    ++stream->errors;
    if ( stream->frames - stream->last_error_frame >= 30*60 )
    {
        char msg[256];

        vsnprintf( msg, sizeof(msg), log, args );

        if ( stream->errors - stream->last_error_count < 10 )
        {
            hb_log( "stream: error near frame %d: %s", stream->frames, msg );
        }
        else
        {
            int Edelta = stream->errors - stream->last_error_count;
            double Epcnt = (double)Edelta * 100. /
                            (stream->frames - stream->last_error_frame);
            hb_log( "stream: %d new errors (%.0f%%) up to frame %d: %s",
                    Edelta, Epcnt, stream->frames, msg );
        }
        stream->last_error_frame = stream->frames;
        stream->last_error_count = stream->errors;
    }
}

static void ts_warn( hb_stream_t *stream, char *log, ... )
{
    va_list     args;
    va_start( args, log );
    ts_warn_helper( stream, log, args );
    va_end( args );
}

static void ts_err( hb_stream_t *stream, int curstream, char *log, ... )
{
    va_list     args;
    va_start( args, log );
    ts_warn_helper( stream, log, args );
    va_end( args );

    stream->ts_skipbad[curstream] = 1;
    stream->ts_pos[curstream] = 0;
    stream->ts_streamcont[curstream] = -1;
}

static int isIframe( const uint8_t *buf, int adapt_len )
{
    // Look for the Group of Pictures packet
    int i;
    uint32_t strid = 0;

    for (i = 4 + adapt_len; i < 188; i++)
    {
        strid = (strid << 8) | buf[i];
        switch ( strid )
        {
            case 0x000001B8: // group_start_code (GOP header)
            case 0x000001B3: // sequence_header code
                return 1;

            case 0x00000100: // picture_start_code
                // picture_header, let's see if it's an I-frame
                if (i<185)
                {
                    // check if picture_coding_type == 1
                    if ((buf[i+2] & (0x7 << 3)) == (1 << 3))
                    {
                        // found an I-frame picture
                        return 1;
                    }
                }
                break;
        }
    }
    // didn't find an I frame
    return 0;
}

/***********************************************************************
 * hb_ts_stream_decode
 ***********************************************************************
 *
 **********************************************************************/
static int hb_ts_stream_decode( hb_stream_t *stream, uint8_t *obuf )
{
    int64_t pcr = stream->ts_lastpcr;
	int curstream;
	uint8_t buf[188];

    /*
     * stash the output buffer pointer in our stream so we don't have to
     * pass it & its original value to everything we call.
     */
    stream->fwrite_buf = obuf;
    stream->fwrite_buf_orig = obuf;

	// spin until we get a packet of data from some stream or hit eof
	while ( 1 )
	{
        if ((fread(buf, 188, 1, stream->file_handle)) != 1)
		{
            // end of file - we didn't finish filling our ps write buffer
            // so just discard the remainder (the partial buffer is useless)
            hb_log("hb_ts_stream_decode - eof");
            return 0;
		}

        /* This next section validates the packet */

		// Check sync byte
		if ((buf[0] != 0x47) && (buf[0] != 0x72) && (buf[0] != 0x29))
		{
            // lost sync - back up to where we started then try to
            // re-establish sync.
            off_t pos = ftello(stream->file_handle) - 188;
            off_t pos2 = align_to_next_packet(stream->file_handle);
            if ( pos2 == 0 )
            {
                hb_log( "hb_ts_stream_decode: eof while re-establishing sync @ %lld",
                        pos );
                return 0;
            }
            ts_warn( stream, "hb_ts_stream_decode: sync lost @%lld, "
                     "regained after %lld bytes", pos, pos2 );
			continue;
		}

		// Get pid and use it to find stream state.
		int pid = ((buf[1] & 0x1F) << 8) | buf[2];
        if ( ( curstream = index_of_pid( pid, stream ) ) < 0 )
            continue;

		// Get error
		int errorbit = (buf[1] & 0x80) != 0;
		if (errorbit)
		{
			ts_err( stream, curstream,  "packet error bit set");
			continue;
		}

		// Get adaption header info
		int adaption = (buf[3] & 0x30) >> 4;
		int adapt_len = 0;
		if (adaption == 0)
		{
			ts_err( stream, curstream,  "adaptation code 0");
			continue;
		}
		else if (adaption == 0x2)
			adapt_len = 184;
		else if (adaption == 0x3)
		{
			adapt_len = buf[4] + 1;
			if (adapt_len > 184)
			{
				ts_err( stream, curstream,  "invalid adapt len %d", adapt_len);
                continue;
			}
		}

        // if there's an adaptation header & PCR_flag is set
        // get the PCR (Program Clock Reference)
        if ( adapt_len > 7 && ( buf[5] & 0x10 ) != 0 )
        {
            pcr = ( (uint64_t)buf[6] << (33 - 8) ) |
                  ( (uint64_t)buf[7] << (33 - 16) ) |
                  ( (uint64_t)buf[8] << (33 - 24) ) |
                  ( (uint64_t)buf[9] << (33 - 32) ) |
                  ( buf[10] >> 7 );
            stream->ts_nextpcr = pcr;

            // remember the pcr across calls to this routine
            stream->ts_lastpcr = pcr;
        }

		if ( pcr == -1 )
		{
            // don't accumulate data until we get a pcr
		    continue;
		}

		// Get continuity
        // Continuity only increments for adaption values of 0x3 or 0x01
        // and is not checked for start packets.

		int start = (buf[1] & 0x40) != 0;

        if ( (adaption & 0x01) != 0 )
		{
            int continuity = (buf[3] & 0xF);
            if ( continuity == stream->ts_streamcont[curstream] )
            {
                // we got a duplicate packet (usually used to introduce
                // a PCR when one is needed). The only thing that can
                // change in the dup is the PCR which we grabbed above
                // so ignore the rest.
                continue;
            }
            if ( !start && (stream->ts_streamcont[curstream] != -1) &&
                 (continuity != ( (stream->ts_streamcont[curstream] + 1) & 0xf ) ) )
			{
				ts_err( stream, curstream,  "continuity error: got %d expected %d",
                        (int)continuity,
                        (stream->ts_streamcont[curstream] + 1) & 0xf );
                stream->ts_streamcont[curstream] = continuity;
				continue;
			}
			stream->ts_streamcont[curstream] = continuity;
		}

        /* If we get here the packet is valid - process its data */

        if ( start )
        {
            // Found a random access point (now we can start a frame/audio packet..)

			// If we were skipping a bad packet, start fresh on this new PES packet..
			if (stream->ts_skipbad[curstream] == 1)
			{
                // video skips to an iframe after a bad packet to minimize
                // screen corruption
                if ( curstream == 0 && !isIframe( buf, adapt_len ) )
                {
                    continue;
                }
				stream->ts_skipbad[curstream] = 0;
			}

			// If we don't have video yet, check to see if this is an
            // i_frame (group of picture start)
			if ( curstream == 0 )
            {
                if ( !stream->ts_foundfirst[0] )
                {
                    if ( !isIframe( buf, adapt_len ) )
                    {
                        // didn't find an I frame
                        continue;
                    }
                    stream->ts_foundfirst[0] = 1;
                }
                ++stream->frames;
            }
			else if ( ! stream->ts_foundfirst[curstream] )
            {
                // start other streams only after first video frame found.
                if ( ! stream->ts_foundfirst[0] )
                {
                    continue;
                }
                stream->ts_foundfirst[curstream] = 1;
			}

            // If we have some data already on this stream, turn it into
            // a program stream packet. Then add the payload for this
            // packet to the current pid's buffer.
            if ( stream->ts_pos[curstream] )
            {
                generate_output_data(stream, curstream);
                stream->ts_start[curstream] = 1;
                memcpy(stream->ts_buf[curstream],
                       buf + 4 + adapt_len, 184 - adapt_len);
                stream->ts_pos[curstream] = 184 - adapt_len;
                return 1;
            }
            stream->ts_start[curstream] = 1;
        }

		// Add the payload for this packet to the current buffer
		if (!stream->ts_skipbad[curstream] && stream->ts_foundfirst[curstream] &&
            (184 - adapt_len) > 0)
		{
			memcpy(stream->ts_buf[curstream] + stream->ts_pos[curstream],
                   buf + 4 + adapt_len, 184 - adapt_len);
			stream->ts_pos[curstream] += 184 - adapt_len;

            // if the next TS packet could possibly overflow our 2K output buffer
            // we need to generate a packet now. Overflow would be 184 bytes of
            // data + the 9 byte PES hdr + the 14 byte PACK hdr = 211 bytes.
            if ( stream->ts_pos[curstream] >= (HB_DVD_READ_BUFFER_SIZE - 216) )
            {
                // we have enough data to make a PS packet
                generate_output_data(stream, curstream);
                return 1;
            }
		}
	}
}

/***********************************************************************
 * hb_ts_stream_reset
 ***********************************************************************
 *
 **********************************************************************/
static void hb_ts_stream_reset(hb_stream_t *stream)
{
	int i;

	for (i=0; i < kMaxNumberDecodeStreams; i++)
	{
		stream->ts_pos[i] = 0;
		stream->ts_foundfirst[i] = 0;
		stream->ts_skipbad[i] = 0;
		stream->ts_streamcont[i] = -1;
		stream->ts_start[i] = 0;
	}

    stream->ts_lastpcr = -1;
    stream->ts_nextpcr = -1;

    stream->frames = 0;
    stream->errors = 0;
    stream->last_error_frame = -10000;
    stream->last_error_count = 0;

	align_to_next_packet(stream->file_handle);
}