path: root/libhb/encavcodec.c

/* $Id: encavcodec.c,v 1.23 2005/10/13 23:47:06 titer Exp $

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

#include "hb.h"
#include "hbffmpeg.h"

struct hb_work_private_s
{
    hb_job_t * job;
    AVCodecContext * context;
    FILE * file;
};

int  encavcodecInit( hb_work_object_t *, hb_job_t * );
int  encavcodecWork( hb_work_object_t *, hb_buffer_t **, hb_buffer_t ** );
void encavcodecClose( hb_work_object_t * );

hb_work_object_t hb_encavcodec =
{
    WORK_ENCAVCODEC,
    "MPEG-4 encoder (libavcodec)",
    encavcodecInit,
    encavcodecWork,
    encavcodecClose
};

int encavcodecInit( hb_work_object_t * w, hb_job_t * job )
{
    AVCodec * codec;
    AVCodecContext * context;
    int rate_num, rate_den;

    hb_work_private_t * pv = calloc( 1, sizeof( hb_work_private_t ) );
    w->private_data = pv;

    pv->job = job;

    codec = avcodec_find_encoder( CODEC_ID_MPEG4 );
    if( !codec )
    {
        hb_log( "hb_work_encavcodec_init: avcodec_find_encoder "
                "failed" );
    }
    context = avcodec_alloc_context();
    if( job->vquality < 0.0 )
    {
        /* Rate control */
        context->bit_rate = 1000 * job->vbitrate;
        context->bit_rate_tolerance = 10 * context->bit_rate;
    }
    else
    {
        /* Constant quantizer */
        // These settings produce better image quality than
        // what was previously used
        context->flags |= CODEC_FLAG_QSCALE;
        if (job->vquality < 1.0)
        {
            float vquality;
            vquality = 31 - job->vquality * 31;
            // A value of 0 has undefined behavior
            // and ffmpeg qp has integral increments
            if (vquality < 1.0)
                vquality = 1.0;
            context->global_quality = FF_QP2LAMBDA * vquality + 0.5;
        }
        else
        {
            context->global_quality = FF_QP2LAMBDA * job->vquality + 0.5;
        }
        context->mb_decision = 1;
        hb_log( "encavcodec: encoding at constant quantizer %d",
                context->global_quality );
    }
    context->width     = job->width;
    context->height    = job->height;
    rate_num = job->vrate_base;
    rate_den = job->vrate;
    if (rate_den == 27000000)
    {
        int ii;
        for (ii = 0; ii < hb_video_rates_count; ii++)
        {
            if (abs(rate_num - hb_video_rates[ii].rate) < 10)
            {
                rate_num = hb_video_rates[ii].rate;
                break;
            }
        }
    }
    hb_reduce(&rate_num, &rate_den, rate_num, rate_den);
    if ((rate_num & ~0xFFFF) || (rate_den & ~0xFFFF))
    {
        hb_log( "encavcodec: truncating framerate %d / %d", 
                rate_num, rate_den );
    }
    while ((rate_num & ~0xFFFF) || (rate_den & ~0xFFFF))
    {
        rate_num >>= 1;
        rate_den >>= 1;
    }
    context->time_base = (AVRational) { rate_num, rate_den };
    context->gop_size  = 10 * job->vrate / job->vrate_base;
    context->pix_fmt   = PIX_FMT_YUV420P;

    if( job->anamorphic.mode )
    {
        context->sample_aspect_ratio.num = job->anamorphic.par_width;
        context->sample_aspect_ratio.den = job->anamorphic.par_height;

        hb_log( "encavcodec: encoding with stored aspect %d/%d",
                job->anamorphic.par_width, job->anamorphic.par_height );
    }

    if( job->mux & ( HB_MUX_MP4 | HB_MUX_PSP ) )
    {
        context->flags |= CODEC_FLAG_GLOBAL_HEADER;
    }
    if( job->mux & HB_MUX_PSP )
    {
        context->flags |= CODEC_FLAG_BITEXACT;
    }
    if( job->grayscale )
    {
        context->flags |= CODEC_FLAG_GRAY;
    }

    if( job->pass != 0 && job->pass != -1 )
    {
        char filename[1024]; memset( filename, 0, 1024 );
        hb_get_tempory_filename( job->h, filename, "ffmpeg.log" );

        if( job->pass == 1 )
        {
            pv->file = fopen( filename, "wb" );
            context->flags |= CODEC_FLAG_PASS1;
        }
        else
        {
            int    size;
            char * log;

            pv->file = fopen( filename, "rb" );
            fseek( pv->file, 0, SEEK_END );
            size = ftell( pv->file );
            fseek( pv->file, 0, SEEK_SET );
            log = malloc( size + 1 );
            log[size] = '\0';
            fread( log, size, 1, pv->file );
            fclose( pv->file );
            pv->file = NULL;

            context->flags    |= CODEC_FLAG_PASS2;
            context->stats_in  = log;
        }
    }

    if( hb_avcodec_open( context, codec ) )
    {
        hb_log( "hb_work_encavcodec_init: avcodec_open failed" );
    }
    pv->context = context;

    if( ( job->mux & ( HB_MUX_MP4 | HB_MUX_PSP ) ) && job->pass != 1 )
    {
#if 0
        /* Hem hem */
        w->config->mpeg4.length = 15;
        memcpy( w->config->mpeg4.bytes, context->extradata + 15, 15 );
#else
        w->config->mpeg4.length = context->extradata_size;
        memcpy( w->config->mpeg4.bytes, context->extradata,
                context->extradata_size );
#endif
    }

    return 0;
}

/***********************************************************************
 * Close
 ***********************************************************************
 *
 **********************************************************************/
void encavcodecClose( hb_work_object_t * w )
{
    hb_work_private_t * pv = w->private_data;

    if( pv->context )
    {
        hb_deep_log( 2, "encavcodec: closing libavcodec" );
        avcodec_flush_buffers( pv->context );
        hb_avcodec_close( pv->context );
    }
    if( pv->file )
    {
        fclose( pv->file );
    }
    free( pv );
    w->private_data = NULL;
}

/***********************************************************************
 * Work
 ***********************************************************************
 *
 **********************************************************************/
int encavcodecWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
                    hb_buffer_t ** buf_out )
{
    hb_work_private_t * pv = w->private_data;
    hb_job_t * job = pv->job;
    AVFrame  * frame;
    hb_buffer_t * in = *buf_in, * buf;

    if ( in->size <= 0 )
    {
        /* EOF on input - send it downstream & say we're done */
        *buf_out = in;
        *buf_in = NULL;
       return HB_WORK_DONE;
    }

    frame              = avcodec_alloc_frame();
    frame->data[0]     = in->data;
    frame->data[1]     = frame->data[0] + job->width * job->height;
    frame->data[2]     = frame->data[1] + job->width * job->height / 4;
    frame->linesize[0] = job->width;
    frame->linesize[1] = job->width / 2;
    frame->linesize[2] = job->width / 2;
    // For constant quality, setting the quality in AVCodecContext 
    // doesn't do the trick.  It must be set in the AVFrame.
    frame->quality = pv->context->global_quality;

    if ( pv->context->codec )
    {
        /* Should be way too large */
        buf = hb_video_buffer_init( job->width, job->height );
        buf->size = avcodec_encode_video( pv->context, buf->data, buf->alloc,
                                          frame );
        buf->start = in->start;
        buf->stop  = in->stop;
        buf->frametype   = pv->context->coded_frame->key_frame ? HB_FRAME_KEY : HB_FRAME_REF;
    }
    else
    {
        buf = NULL;
        
        hb_error( "encavcodec: codec context has uninitialized codec; skipping frame" );
    }

    av_free( frame );

    if( job->pass == 1 )
    {
        /* Write stats */
        fprintf( pv->file, "%s", pv->context->stats_out );
    }

    *buf_out = buf;

    return HB_WORK_OK;
}