diff options
| -rw-r--r-- | DOCS/man/options.rst | 14 | ||||
| -rw-r--r-- | demux/demux_lavf.c | 68 |
2 files changed, 67 insertions, 15 deletions
diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst index 74ea73be98..ce31635192 100644 --- a/DOCS/man/options.rst +++ b/DOCS/man/options.rst @@ -445,7 +445,9 @@ Playback Control their behavior. There is no list, and the player usually does not detect them. Certain live streams (including TV captures) may exhibit problems in particular, as well as some lossy audio codecs. h264 intra-refresh is - known not to work due to problems with libavcodec. + known not to work due to problems with libavcodec. WAV and some other raw + audio formats tend to have problems - there are hacks for dealing with + them, which may or may not work. - Function with EDL/mkv ordered chapters is obviously broken. @@ -478,16 +480,6 @@ Playback Control framestep commands are transposed. Backstepping will perform very expensive work to step forward by 1 frame. - - Backward playback in wav files does not work properly (and possibly - similar formats, typically raw audio formats used through libavformat). - This is because libavformat does not align seeks on the packet sizes it - uses. (The packet sizes are arbitrary and chosen by libavformat - internally. Seeks on the other hand are sample-exact, which leads to - overlapping packets if the backward playback state machine seeks back. - This is very complex to work around, so it doesn't attempt to.) - A workaround is to remux to a format like mkv, which enforces packet - boundaries. Making mpv cache the entire file in memory also works. - - Backward playback with Vorbis does not work. libavcodec's decoder discards the first Vorbis packet (after each decoder reset), and the mechanism behind ``--audio-reversal-buffer`` assumes that it strictly diff --git a/demux/demux_lavf.c b/demux/demux_lavf.c index 283e6fe6fb..e0bf24fd50 100644 --- a/demux/demux_lavf.c +++ b/demux/demux_lavf.c @@ -140,6 +140,7 @@ struct format_hack { bool fix_editlists : 1; bool is_network : 1; bool no_seek : 1; + bool no_pcm_seek : 1; }; #define BLACKLIST(fmt) {fmt, .ignore = true} @@ -161,8 +162,8 @@ static const struct format_hack format_hacks[] = { {"mpeg", .use_stream_ids = true}, {"mpegts", .use_stream_ids = true}, - {"mp4", .skipinfo = true, .fix_editlists = true}, - {"matroska", .skipinfo = true}, + {"mp4", .skipinfo = true, .fix_editlists = true, .no_pcm_seek = true}, + {"matroska", .skipinfo = true, .no_pcm_seek = true}, {"v4l2", .no_seek = true}, @@ -217,6 +218,10 @@ typedef struct lavf_priv { struct demux_lavf_opts *opts; double mf_fps; + bool pcm_seek_hack_disabled; + AVStream *pcm_seek_hack; + int pcm_seek_hack_packet_size; + // Proxying nested streams. struct nested_stream *nested; int num_nested; @@ -677,6 +682,12 @@ static void handle_new_stream(demuxer_t *demuxer, int i) } } + if (!sh->attached_picture) { + // A real video stream probably means it's a packet based format. + priv->pcm_seek_hack_disabled = true; + priv->pcm_seek_hack = NULL; + } + sh->codec->disp_w = codec->width; sh->codec->disp_h = codec->height; if (st->avg_frame_rate.num) @@ -785,6 +796,25 @@ static void handle_new_stream(demuxer_t *demuxer, int i) sh->missing_timestamps = !!(priv->avif_flags & AVFMT_NOTIMESTAMPS); mp_tags_copy_from_av_dictionary(sh->tags, st->metadata); demux_add_sh_stream(demuxer, sh); + + // Unfortunately, there is no better way to detect PCM codecs, other + // than listing them all manually. (Or other "frameless" codecs. Or + // rather, codecs with frames so small libavformat will put multiple of + // them into a single packet, but not preserve these artificial packet + // boundaries on seeking.) + if (sh->codec->codec && strncmp(sh->codec->codec, "pcm_", 4) == 0 && + codec->block_align && !priv->pcm_seek_hack_disabled && + priv->opts->hacks && !priv->format_hack.no_pcm_seek && + st->time_base.num == 1 && st->time_base.den == codec->sample_rate) + { + if (priv->pcm_seek_hack) { + // More than 1 audio stream => usually doesn't apply. + priv->pcm_seek_hack_disabled = true; + priv->pcm_seek_hack = NULL; + } else { + priv->pcm_seek_hack = st; + } + } } select_tracks(demuxer, i); @@ -1112,6 +1142,9 @@ static bool demux_lavf_read_packet(struct demuxer *demux, return true; } + if (priv->pcm_seek_hack == st && !priv->pcm_seek_hack_packet_size) + priv->pcm_seek_hack_packet_size = pkt->size; + if (pkt->pts != AV_NOPTS_VALUE) dp->pts = pkt->pts * av_q2d(st->time_base); if (pkt->dts != AV_NOPTS_VALUE) @@ -1139,6 +1172,7 @@ static void demux_seek_lavf(demuxer_t *demuxer, double seek_pts, int flags) lavf_priv_t *priv = demuxer->priv; int avsflags = 0; int64_t seek_pts_av = 0; + int seek_stream = -1; if (priv->optical_crap_hack) { if (flags & SEEK_FACTOR) @@ -1169,13 +1203,39 @@ static void demux_seek_lavf(demuxer_t *demuxer, double seek_pts, int flags) seek_pts_av = seek_pts * AV_TIME_BASE; } - int r = av_seek_frame(priv->avfc, -1, seek_pts_av, avsflags); + // Hack to make wav seeking "deterministic". Without this, features like + // backward playback won't work. + if (priv->pcm_seek_hack && !priv->pcm_seek_hack_packet_size) { + // This might for example be the initial seek. Fuck it up like the + // bullshit it is. + AVPacket pkt = {0}; + if (av_read_frame(priv->avfc, &pkt) >= 0) + priv->pcm_seek_hack_packet_size = pkt.size; + av_packet_unref(&pkt); + add_new_streams(demuxer); + } + if (priv->pcm_seek_hack && priv->pcm_seek_hack_packet_size && + !(avsflags & AVSEEK_FLAG_BYTE)) + { + int samples = priv->pcm_seek_hack_packet_size / + priv->pcm_seek_hack->codecpar->block_align; + if (samples > 0) { + MP_VERBOSE(demuxer, "using bullshit libavformat PCM seek hack\n"); + double pts = seek_pts_av / (double)AV_TIME_BASE; + seek_pts_av = pts / av_q2d(priv->pcm_seek_hack->time_base); + int64_t align = seek_pts_av % samples; + seek_pts_av -= align; + seek_stream = priv->pcm_seek_hack->index; + } + } + + int r = av_seek_frame(priv->avfc, seek_stream, seek_pts_av, avsflags); if (r < 0 && (avsflags & AVSEEK_FLAG_BACKWARD)) { // When seeking before the beginning of the file, and seeking fails, // try again without the backwards flag to make it seek to the // beginning. avsflags &= ~AVSEEK_FLAG_BACKWARD; - r = av_seek_frame(priv->avfc, -1, seek_pts_av, avsflags); + r = av_seek_frame(priv->avfc, seek_stream, seek_pts_av, avsflags); } if (r < 0) { |