/* decpgssub.c Copyright (c) 2003-2013 HandBrake Team 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 v2. For full terms see the file COPYING file or visit http://www.gnu.org/licenses/gpl-2.0.html */ #include "hb.h" #include "hbffmpeg.h" struct hb_work_private_s { AVCodecContext * context; hb_job_t * job; // For PGS subs, when doing passthru, we don't know if we need a // packet until we have processed several packets. So we cache // all the packets we see until libav returns a subtitle with // the information we need. hb_buffer_t * list_pass_buffer; hb_buffer_t * last_pass_buffer; // It is possible for multiple subtitles to be enncapsulated in // one packet. This won't happen for PGS subs, but may for other // types of subtitles. Since I plan to generalize this code to handle // other than PGS, we will need to keep a list of all subtitles seen // while parsing an input packet. hb_buffer_t * list_buffer; hb_buffer_t * last_buffer; // XXX: we may occasionally see subtitles with broken timestamps // while this should really get fixed elsewhere, // dropping subtitles should be avoided as much as possible int64_t last_pts; // for PGS subs, we need to pass 'empty' subtitles through (they clear the // display) - when doing forced-only extraction, only pass empty subtitles // through if we've seen a forced sub and haven't seen any empty sub since uint8_t seen_forced_sub; // if we start encoding partway through the source, we may encounter empty // subtitles before we see any actual subtitle content - discard them uint8_t discard_subtitle; }; static int decsubInit( hb_work_object_t * w, hb_job_t * job ) { AVCodec *codec = avcodec_find_decoder( AV_CODEC_ID_HDMV_PGS_SUBTITLE ); AVCodecContext *context = avcodec_alloc_context3( codec ); context->codec = codec; hb_work_private_t * pv; pv = calloc( 1, sizeof( hb_work_private_t ) ); w->private_data = pv; pv->discard_subtitle = 1; pv->seen_forced_sub = 0; pv->last_pts = 0; pv->context = context; pv->job = job; // Set decoder opts... AVDictionary * av_opts = NULL; // e.g. av_dict_set( &av_opts, "refcounted_frames", "1", 0 ); if (hb_avcodec_open(pv->context, codec, &av_opts, 0)) { av_dict_free( &av_opts ); hb_log("decsubInit: avcodec_open failed"); return 1; } av_dict_free( &av_opts ); return 0; } static void make_empty_pgs( hb_buffer_t * buf ) { hb_buffer_t * b = buf; uint8_t done = 0; // Each buffer is composed of 1 or more segments. // Segment header is: // type - 1 byte // length - 2 bytes // We want to modify the presentation segment which is type 0x16 // // Note that every pgs display set is required to have a presentation // segment, so we will only have to look at one display set. while ( b && !done ) { int ii = 0; while (ii + 3 <= b->size) { uint8_t type; int len; int segment_len_pos; type = b->data[ii++]; segment_len_pos = ii; len = ((int)b->data[ii] << 8) + b->data[ii+1]; ii += 2; if (type == 0x16 && ii + len <= b->size) { int obj_count; int kk, jj = ii; int obj_start; // Skip // video descriptor 5 bytes // composition descriptor 3 bytes // palette update flg 1 byte // palette id ref 1 byte jj += 10; // Set number of composition objects to 0 obj_count = b->data[jj]; b->data[jj] = 0; jj++; obj_start = jj; // And remove all the composition objects for (kk = 0; kk < obj_count; kk++) { uint8_t crop; crop = b->data[jj + 3]; // skip // object id - 2 bytes // window id - 1 byte // object/forced flag - 1 byte // x pos - 2 bytes // y pos - 2 bytes jj += 8; if (crop & 0x80) { // skip // crop x - 2 bytes // crop y - 2 bytes // crop w - 2 bytes // crop h - 2 bytes jj += 8; } } if (jj < b->size) { memmove(b->data + obj_start, b->data + jj, b->size - jj); } b->size = obj_start + ( b->size - jj ); done = 1; len = obj_start - (segment_len_pos + 2); b->data[segment_len_pos] = len >> 8; b->data[segment_len_pos+1] = len & 0xff; break; } ii += len; } b = b->next; } } static int decsubWork( hb_work_object_t * w, hb_buffer_t ** buf_in, hb_buffer_t ** buf_out ) { hb_work_private_t * pv = w->private_data; hb_buffer_t * in = *buf_in; if ( in->size <= 0 ) { /* EOF on input stream - send it downstream & say that we're done */ if ( pv->list_buffer == NULL ) { pv->list_buffer = pv->last_buffer = in; } else { pv->last_buffer->next = in; } *buf_in = NULL; *buf_out = pv->list_buffer; pv->list_buffer = NULL; return HB_WORK_DONE; } if ( !pv->job->indepth_scan && w->subtitle->config.dest == PASSTHRUSUB && hb_subtitle_can_pass( PGSSUB, pv->job->mux ) ) { // Append to buffer list. It will be sent to fifo after we determine // if this is a packet we need. if ( pv->list_pass_buffer == NULL ) { pv->list_pass_buffer = pv->last_pass_buffer = in; } else { pv->last_pass_buffer->next = in; pv->last_pass_buffer = in; } // We are keeping the buffer, so prevent the filter loop from // deleting it. *buf_in = NULL; } AVSubtitle subtitle; memset( &subtitle, 0, sizeof(subtitle) ); AVPacket avp; av_init_packet( &avp ); avp.data = in->data; avp.size = in->size; // libav wants pkt pts in AV_TIME_BASE units if (in->s.start != AV_NOPTS_VALUE) { avp.pts = av_rescale(in->s.start, AV_TIME_BASE, 90000); } else { avp.pts = AV_NOPTS_VALUE; } int has_subtitle = 0; do { int usedBytes = avcodec_decode_subtitle2( pv->context, &subtitle, &has_subtitle, &avp ); if (usedBytes < 0) { hb_log("unable to decode subtitle with %d bytes.", avp.size); return HB_WORK_OK; } if (usedBytes <= avp.size) { avp.data += usedBytes; avp.size -= usedBytes; } else { avp.size = 0; } /* Subtitles are "usable" if: * 1. Libav returned a subtitle (has_subtitle) AND * 2. we're not doing Foreign Audio Search (!pv->job->indepth_scan) AND * 3. the sub is non-empty or we've seen one such sub before (!pv->discard_subtitle) * For forced-only extraction, usable subtitles also need to: * a. be forced (subtitle.rects[0]->flags & AV_SUBTITLE_FLAG_FORCED) OR * b. follow a forced sub (pv->seen_forced_sub) */ uint8_t forced_sub = 0; uint8_t useable_sub = 0; uint8_t clear_subtitle = 0; if (has_subtitle) { // subtitle statistics if (subtitle.num_rects) { w->subtitle->hits++; if (subtitle.rects[0]->flags & AV_SUBTITLE_FLAG_FORCED) { forced_sub = 1; w->subtitle->forced_hits++; } } else { clear_subtitle = 1; } // are we doing Foreign Audio Search? if (!pv->job->indepth_scan) { // do we want to discard this subtitle? pv->discard_subtitle = pv->discard_subtitle && clear_subtitle; // do we need this subtitle? useable_sub = (!pv->discard_subtitle && (!w->subtitle->config.force || forced_sub || pv->seen_forced_sub)); // do we need to create an empty subtitle? if (w->subtitle->config.force && useable_sub && !forced_sub && !clear_subtitle) { // We are forced-only and need to output this subtitle, but // it's neither forced nor empty. // // If passthru, create an empty subtitle. // Also, flag an empty subtitle for subtitle RENDER. make_empty_pgs(pv->list_pass_buffer); clear_subtitle = 1; } // is the subtitle forced? pv->seen_forced_sub = forced_sub; } } if (useable_sub) { int64_t pts = AV_NOPTS_VALUE; hb_buffer_t * out = NULL; if (subtitle.pts != AV_NOPTS_VALUE) { pts = av_rescale(subtitle.pts, 90000, AV_TIME_BASE); } else { if (in->s.start >= 0) { pts = in->s.start; } else { // XXX: a broken pts will cause us to drop this subtitle, // which is bad; use a default duration of 3 seconds // // A broken pts is only generated when a pgs packet // occurs after a discontinuity and before the // next audio or video packet which re-establishes // timing (afaik). pts = pv->last_pts + 3 * 90000LL; hb_log("[warning] decpgssub: track %d, invalid PTS", w->subtitle->out_track); } } // work around broken timestamps if (pts < pv->last_pts) { // XXX: this should only happen if the prevous pts // was unknown and our 3 second default duration // overshot the next pgs pts. // // assign a 1 second duration pts = pv->last_pts + 1 * 90000LL; hb_log("[warning] decpgssub: track %d, non-monotically increasing PTS", w->subtitle->out_track); } pv->last_pts = pts; if ( w->subtitle->config.dest == PASSTHRUSUB && hb_subtitle_can_pass( PGSSUB, pv->job->mux ) ) { /* PGS subtitles are spread across multiple packets (1 per segment). * In the MKV container, all segments are found in the same packet * (this is expected by some devices, such as the WD TV Live). * So if there are multiple packets, merge them. */ if (pv->list_pass_buffer->next == NULL) { // packets already merged (e.g. MKV sources) out = pv->list_pass_buffer; pv->list_pass_buffer = NULL; } else { int size = 0; uint8_t * data; hb_buffer_t * b; b = pv->list_pass_buffer; while (b != NULL) { size += b->size; b = b->next; } out = hb_buffer_init( size ); data = out->data; b = pv->list_pass_buffer; while (b != NULL) { memcpy( data, b->data, b->size ); data += b->size; b = b->next; } hb_buffer_close( &pv->list_pass_buffer ); out->s = in->s; out->s.frametype = HB_FRAME_SUBTITLE; out->sequence = in->sequence; } out->s.renderOffset = AV_NOPTS_VALUE; out->s.start = out->s.stop = pts; } else { if (!clear_subtitle) { unsigned ii; for (ii = 0; ii < subtitle.num_rects; ii++) { AVSubtitleRect *rect = subtitle.rects[ii]; out = hb_frame_buffer_init(AV_PIX_FMT_YUVA420P, rect->w, rect->h); out->s.frametype = HB_FRAME_SUBTITLE; out->s.id = in->s.id; out->sequence = in->sequence; out->s.start = pts; out->s.stop = pts; out->f.x = rect->x; out->f.y = rect->y; uint8_t *lum = out->plane[0].data; uint8_t *chromaU = out->plane[1].data; uint8_t *chromaV = out->plane[2].data; uint8_t *alpha = out->plane[3].data; int xx, yy; for (yy = 0; yy < rect->h; yy++) { for (xx = 0; xx < rect->w; xx++) { uint32_t argb, yuv; int pixel; uint8_t color; pixel = yy * rect->w + xx; color = rect->pict.data[0][pixel]; argb = ((uint32_t*)rect->pict.data[1])[color]; yuv = hb_rgb2yuv(argb); lum[xx] = (yuv >> 16) & 0xff; alpha[xx] = (argb >> 24) & 0xff; if ((xx & 1) == 0 && (yy & 1) == 0) { chromaV[xx>>1] = (yuv >> 8) & 0xff; chromaU[xx>>1] = yuv & 0xff; } } lum += out->plane[0].stride; if ((yy & 1) == 0) { chromaU += out->plane[1].stride; chromaV += out->plane[2].stride; } alpha += out->plane[3].stride; } if ( pv->list_buffer == NULL ) { pv->list_buffer = pv->last_buffer = out; } else { pv->last_buffer->next = out; pv->last_buffer = out; } out = NULL; } } else { out = hb_buffer_init( 1 ); out->s.frametype = HB_FRAME_SUBTITLE; out->s.id = in->s.id; out->s.start = pts; out->s.stop = pts; out->f.x = 0; out->f.y = 0; out->f.width = 0; out->f.height = 0; } } if ( pv->list_buffer == NULL ) { pv->list_buffer = pv->last_buffer = out; } else { pv->last_buffer->next = out; } while (pv->last_buffer && pv->last_buffer->next) { pv->last_buffer = pv->last_buffer->next; } } else if ( has_subtitle ) { hb_buffer_close( &pv->list_pass_buffer ); pv->list_pass_buffer = NULL; } if ( has_subtitle ) { avsubtitle_free(&subtitle); } } while (avp.size > 0); *buf_out = pv->list_buffer; pv->list_buffer = NULL; return HB_WORK_OK; } static void decsubClose( hb_work_object_t * w ) { hb_work_private_t * pv = w->private_data; avcodec_flush_buffers( pv->context ); avcodec_close( pv->context ); } hb_work_object_t hb_decpgssub = { WORK_DECPGSSUB, "PGS decoder", decsubInit, decsubWork, decsubClose };