diff options
| -rw-r--r-- | Changelog | 1 | ||||
| -rw-r--r-- | doc/ffmpeg.texi | 16 | ||||
| -rw-r--r-- | ffmpeg.c | 178 |
3 files changed, 191 insertions, 4 deletions
@@ -39,6 +39,7 @@ version next: - concat filter - flite filter - Canopus Lossless Codec decoder +- bitmap subtitles in filters (experimental and temporary) version 0.11: diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi index 904a50589a..1ee42d82b4 100644 --- a/doc/ffmpeg.texi +++ b/doc/ffmpeg.texi @@ -989,6 +989,22 @@ ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv @end example @end table +As a special exception, you can use a bitmap subtitle stream as input: it +will be converted into a video with the same size as the largest video in +the file, or 720×576 if no video is present. Note that this is an +experimental and temporary solution. It will be removed once libavfilter has +proper support for subtitles. + +For example, to hardcode subtitles on top of a DVB-T recording stored in +MPEG-TS format, delaying the subtitles by 1 second: +@example +ffmpeg -i input.ts -filter_complex \ + '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \ + -sn -map '#0x2dc' output.mkv +@end example +(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video, +audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too) + @section Preset files A preset file contains a sequence of @var{option}=@var{value} pairs, one for each line, specifying a sequence of options which would be @@ -249,6 +249,12 @@ typedef struct InputStream { int resample_channels; uint64_t resample_channel_layout; + struct sub2video { + int64_t last_pts; + AVFilterBufferRef *ref; + int w, h; + } sub2video; + /* a pool of free buffers for decoded data */ FrameBuffer *buffer_pool; int dr1; @@ -504,6 +510,155 @@ static void update_benchmark(const char *fmt, ...) } } +/* sub2video hack: + Convert subtitles to video with alpha to insert them in filter graphs. + This is a temporary solution until libavfilter gets real subtitles support. + */ + + +static int sub2video_prepare(InputStream *ist) +{ + AVFormatContext *avf = input_files[ist->file_index]->ctx; + int i, ret, w, h; + uint8_t *image[4]; + int linesize[4]; + + /* Compute the size of the canvas for the subtitles stream. + If the subtitles codec has set a size, use it. Otherwise use the + maximum dimensions of the video streams in the same file. */ + w = ist->st->codec->width; + h = ist->st->codec->height; + if (!(w && h)) { + for (i = 0; i < avf->nb_streams; i++) { + if (avf->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) { + w = FFMAX(w, avf->streams[i]->codec->width); + h = FFMAX(h, avf->streams[i]->codec->height); + } + } + if (!(w && h)) { + w = FFMAX(w, 720); + h = FFMAX(h, 576); + } + av_log(avf, AV_LOG_INFO, "sub2video: using %dx%d canvas\n", w, h); + } + ist->sub2video.w = ist->st->codec->width = w; + ist->sub2video.h = ist->st->codec->height = h; + + /* rectangles are PIX_FMT_PAL8, but we have no guarantee that the + palettes for all rectangles are identical or compatible */ + ist->st->codec->pix_fmt = PIX_FMT_RGB32; + + ret = av_image_alloc(image, linesize, w, h, PIX_FMT_RGB32, 32); + if (ret < 0) + return ret; + memset(image[0], 0, h * linesize[0]); + ist->sub2video.ref = avfilter_get_video_buffer_ref_from_arrays( + image, linesize, AV_PERM_READ | AV_PERM_PRESERVE, + w, h, PIX_FMT_RGB32); + if (!ist->sub2video.ref) { + av_free(image[0]); + return AVERROR(ENOMEM); + } + return 0; +} + +static void sub2video_copy_rect(uint8_t *dst, int dst_linesize, int w, int h, + AVSubtitleRect *r) +{ + uint32_t *pal, *dst2; + uint8_t *src, *src2; + int x, y; + + if (r->type != SUBTITLE_BITMAP) { + av_log(NULL, AV_LOG_WARNING, "sub2video: non-bitmap subtitle\n"); + return; + } + if (r->x < 0 || r->x + r->w > w || r->y < 0 || r->y + r->h > h) { + av_log(NULL, AV_LOG_WARNING, "sub2video: rectangle overflowing\n"); + return; + } + + dst += r->y * dst_linesize + r->x * 4; + src = r->pict.data[0]; + pal = (uint32_t *)r->pict.data[1]; + for (y = 0; y < r->h; y++) { + dst2 = (uint32_t *)dst; + src2 = src; + for (x = 0; x < r->w; x++) + *(dst2++) = pal[*(src2++)]; + dst += dst_linesize; + src += r->pict.linesize[0]; + } +} + +static void sub2video_push_ref(InputStream *ist, int64_t pts) +{ + AVFilterBufferRef *ref = ist->sub2video.ref; + int i; + + ist->sub2video.last_pts = ref->pts = pts; + for (i = 0; i < ist->nb_filters; i++) + av_buffersrc_add_ref(ist->filters[i]->filter, + avfilter_ref_buffer(ref, ~0), + AV_BUFFERSRC_FLAG_NO_CHECK_FORMAT | + AV_BUFFERSRC_FLAG_NO_COPY); +} + +static void sub2video_update(InputStream *ist, AVSubtitle *sub, int64_t pts) +{ + int w = ist->sub2video.w, h = ist->sub2video.h; + AVFilterBufferRef *ref = ist->sub2video.ref; + int8_t *dst; + int dst_linesize; + int i; + + if (!ref) + return; + dst = ref->data [0]; + dst_linesize = ref->linesize[0]; + memset(dst, 0, h * dst_linesize); + for (i = 0; i < sub->num_rects; i++) + sub2video_copy_rect(dst, dst_linesize, w, h, sub->rects[i]); + sub2video_push_ref(ist, pts); +} + +static void sub2video_heartbeat(InputStream *ist, int64_t pts) +{ + InputFile *infile = input_files[ist->file_index]; + int i, j, nb_reqs; + int64_t pts2; + + /* When a frame is read from a file, examine all sub2video streams in + the same file and send the sub2video frame again. Otherwise, decoded + video frames could be accumulating in the filter graph while a filter + (possibly overlay) is desperately waiting for a subtitle frame. */ + for (i = 0; i < infile->nb_streams; i++) { + InputStream *ist2 = input_streams[infile->ist_index + i]; + if (!ist2->sub2video.ref) + continue; + /* subtitles seem to be usually muxed ahead of other streams; + if not, substracting a larger time here is necessary */ + pts2 = av_rescale_q(pts, ist->st->time_base, ist2->st->time_base) - 1; + /* do not send the heartbeat frame if the subtitle is already ahead */ + if (pts2 <= ist2->sub2video.last_pts) + continue; + for (j = 0, nb_reqs = 0; j < ist2->nb_filters; j++) + nb_reqs += av_buffersrc_get_nb_failed_requests(ist2->filters[j]->filter); + if (nb_reqs) + sub2video_push_ref(ist2, pts2); + } +} + +static void sub2video_flush(InputStream *ist) +{ + int i; + + for (i = 0; i < ist->nb_filters; i++) + av_buffersrc_add_ref(ist->filters[i]->filter, NULL, 0); +} + +/* end of sub2video hack */ + static void reset_options(OptionsContext *o, int is_input) { const OptionDef *po = options; @@ -745,7 +900,10 @@ static void init_input_filter(FilterGraph *fg, AVFilterInOut *in) s = input_files[file_idx]->ctx; for (i = 0; i < s->nb_streams; i++) { - if (s->streams[i]->codec->codec_type != type) + enum AVMediaType stream_type = s->streams[i]->codec->codec_type; + if (stream_type != type && + !(stream_type == AVMEDIA_TYPE_SUBTITLE && + type == AVMEDIA_TYPE_VIDEO /* sub2video hack */)) continue; if (check_stream_specifier(s, s->streams[i], *p == ':' ? p + 1 : p) == 1) { st = s->streams[i]; @@ -1025,6 +1183,12 @@ static int configure_input_video_filter(FilterGraph *fg, InputFilter *ifilter, int pad_idx = in->pad_idx; int ret; + if (ist->st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) { + ret = sub2video_prepare(ist); + if (ret < 0) + return ret; + } + sar = ist->st->sample_aspect_ratio.num ? ist->st->sample_aspect_ratio : ist->st->codec->sample_aspect_ratio; @@ -1413,6 +1577,7 @@ void av_noreturn exit_program(int ret) av_freep(&input_streams[i]->decoded_frame); av_dict_free(&input_streams[i]->opts); free_buffer_pool(&input_streams[i]->buffer_pool); + avfilter_unref_bufferp(&input_streams[i]->sub2video.ref); av_freep(&input_streams[i]->filters); av_freep(&input_streams[i]); } @@ -2636,13 +2801,16 @@ static int transcode_subtitles(InputStream *ist, AVPacket *pkt, int *got_output) AVSubtitle subtitle; int i, ret = avcodec_decode_subtitle2(ist->st->codec, &subtitle, got_output, pkt); - if (ret < 0) - return ret; - if (!*got_output) + if (ret < 0 || !*got_output) { + if (!pkt->size) + sub2video_flush(ist); return ret; + } rate_emu_sleep(ist); + sub2video_update(ist, &subtitle, pkt->pts); + for (i = 0; i < nb_output_streams; i++) { OutputStream *ost = output_streams[i]; @@ -3847,6 +4015,8 @@ static int transcode(void) } } + sub2video_heartbeat(ist, pkt.pts); + // fprintf(stderr,"read #%d.%d size=%d\n", ist->file_index, ist->st->index, pkt.size); if ((ret = output_packet(ist, &pkt)) < 0 || ((ret = poll_filters()) < 0 && ret != AVERROR_EOF)) { |