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avformat/imf: add support for input seeking
The IMF demuxer did not implement AVInputFormat::read_seek2(), resulting in inefficient input seeking. Addresses https://trac.ffmpeg.org/ticket/9648 Byte- and frame-seeking are not supported. Signed-off-by: Zane van Iperen <zane@zanevaniperen.com>
This commit is contained in:
Pierre-Anthony Lemieux
Zane van Iperen
parent
9ca4d80d6b
commit
32b9f5ac2f
@ -359,13 +359,15 @@ static IMFAssetLocator *find_asset_map_locator(IMFAssetLocatorMap *asset_map, FF
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}
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static int open_track_resource_context(AVFormatContext *s,
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IMFVirtualTrackResourcePlaybackCtx *track_resource)
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IMFVirtualTrackPlaybackCtx *track,
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int32_t resource_index)
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{
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IMFContext *c = s->priv_data;
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int ret = 0;
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int64_t entry_point;
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int64_t seek_offset = 0;
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AVDictionary *opts = NULL;
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AVStream *st;
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IMFVirtualTrackResourcePlaybackCtx *track_resource = track->resources + resource_index;
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if (track_resource->ctx) {
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av_log(s,
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@ -416,32 +418,27 @@ static int open_track_resource_context(AVFormatContext *s,
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st = track_resource->ctx->streams[0];
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/* Warn if the resource time base does not match the file time base */
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if (av_cmp_q(st->time_base, av_inv_q(track_resource->resource->base.edit_rate)))
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av_log(s,
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AV_LOG_WARNING,
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"Incoherent source stream timebase " AVRATIONAL_FORMAT
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"regarding resource edit rate: " AVRATIONAL_FORMAT,
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st->time_base.num,
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st->time_base.den,
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track_resource->resource->base.edit_rate.den,
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track_resource->resource->base.edit_rate.num);
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/* Determine the seek offset into the Track File, taking into account:
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* - the current timestamp within the virtual track
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* - the entry point of the resource
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*/
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if (imf_time_to_ts(&seek_offset,
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av_sub_q(track->current_timestamp, track_resource->ts_offset),
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st->time_base))
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av_log(s, AV_LOG_WARNING, "Incoherent stream timebase " AVRATIONAL_FORMAT
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"and composition timeline position: " AVRATIONAL_FORMAT "\n",
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st->time_base.num, st->time_base.den,
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track->current_timestamp.den, track->current_timestamp.num);
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entry_point = av_rescale_q(track_resource->resource->base.entry_point, st->time_base,
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av_inv_q(track_resource->resource->base.edit_rate));
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if (entry_point) {
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av_log(s,
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AV_LOG_DEBUG,
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"Seek at resource %s entry point: %" PRIu32 "\n",
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track_resource->locator->absolute_uri,
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track_resource->resource->base.entry_point);
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ret = avformat_seek_file(track_resource->ctx, 0, entry_point, entry_point, entry_point, 0);
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if (seek_offset) {
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av_log(s, AV_LOG_DEBUG, "Seek at resource %s entry point: %" PRIi64 "\n",
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track_resource->locator->absolute_uri, seek_offset);
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ret = avformat_seek_file(track_resource->ctx, 0, seek_offset, seek_offset, seek_offset, 0);
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if (ret < 0) {
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av_log(s,
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AV_LOG_ERROR,
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"Could not seek at %" PRId64 "on %s: %s\n",
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entry_point,
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seek_offset,
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track_resource->locator->absolute_uri,
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av_err2str(ret));
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avformat_close_input(&track_resource->ctx);
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@ -584,7 +581,7 @@ static int set_context_streams_from_tracks(AVFormatContext *s)
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AVStream *first_resource_stream;
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/* Open the first resource of the track to get stream information */
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ret = open_track_resource_context(s, &c->tracks[i]->resources[0]);
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ret = open_track_resource_context(s, c->tracks[i], 0);
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if (ret)
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return ret;
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first_resource_stream = c->tracks[i]->resources[0].ctx->streams[0];
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@ -774,7 +771,7 @@ static int get_resource_context_for_timestamp(AVFormatContext *s, IMFVirtualTrac
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"Switch resource on track %d: re-open context\n",
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track->index);
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ret = open_track_resource_context(s, track->resources + i);
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ret = open_track_resource_context(s, track, i);
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if (ret != 0)
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return ret;
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if (track->current_resource_index > 0)
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@ -942,6 +939,83 @@ static int imf_probe(const AVProbeData *p)
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return AVPROBE_SCORE_MAX;
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}
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static void rescale_interval(AVRational tb_in, AVRational tb_out,
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int64_t *min_ts, int64_t *ts, int64_t *max_ts)
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{
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*ts = av_rescale_q(*ts, tb_in, tb_out);
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*min_ts = av_rescale_q_rnd(*min_ts, tb_in, tb_out, AV_ROUND_UP | AV_ROUND_PASS_MINMAX);
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*max_ts = av_rescale_q_rnd(*max_ts, tb_in, tb_out, AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);
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}
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static int coherent_ts(int64_t ts, AVRational in_tb, AVRational out_tb)
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{
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int dst_num;
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int dst_den;
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int ret;
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ret = av_reduce(&dst_num, &dst_den, ts * in_tb.num * out_tb.den,
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in_tb.den * out_tb.num, INT64_MAX);
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if (!ret || dst_den != 1)
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return 0;
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return 1;
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}
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static int imf_seek(AVFormatContext *s, int stream_index, int64_t min_ts,
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int64_t ts, int64_t max_ts, int flags)
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{
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IMFContext *c = s->priv_data;
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uint32_t i;
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if (flags & (AVSEEK_FLAG_BYTE | AVSEEK_FLAG_FRAME))
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return AVERROR(ENOSYS);
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/* rescale timestamps to Composition edit units */
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if (stream_index < 0)
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rescale_interval(AV_TIME_BASE_Q,
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av_make_q(c->cpl->edit_rate.den, c->cpl->edit_rate.num),
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&min_ts, &ts, &max_ts);
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else
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rescale_interval(s->streams[stream_index]->time_base,
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av_make_q(c->cpl->edit_rate.den, c->cpl->edit_rate.num),
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&min_ts, &ts, &max_ts);
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/* requested timestamp bounds are too close */
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if (max_ts < min_ts)
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return -1;
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/* clamp requested timestamp to provided bounds */
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ts = FFMAX(FFMIN(ts, max_ts), min_ts);
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av_log(s, AV_LOG_DEBUG, "Seeking to Composition Playlist edit unit %" PRIi64 "\n", ts);
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/* set the dts of each stream and temporal offset of each track */
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for (i = 0; i < c->track_count; i++) {
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AVStream *st = s->streams[i];
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IMFVirtualTrackPlaybackCtx *t = c->tracks[i];
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int64_t dts;
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if (!coherent_ts(ts, av_make_q(c->cpl->edit_rate.den, c->cpl->edit_rate.num),
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st->time_base))
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av_log(s, AV_LOG_WARNING, "Seek position is not coherent across tracks\n");
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dts = av_rescale(ts,
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st->time_base.den * c->cpl->edit_rate.den,
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st->time_base.num * c->cpl->edit_rate.num);
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av_log(s, AV_LOG_DEBUG, "Seeking to dts=%" PRId64 " on stream_index=%d\n",
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dts, i);
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t->current_timestamp = av_mul_q(av_make_q(dts, 1), st->time_base);
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if (t->current_resource_index >= 0) {
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avformat_close_input(&t->resources[t->current_resource_index].ctx);
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t->current_resource_index = -1;
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}
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}
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return 0;
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}
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static const AVOption imf_options[] = {
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{
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.name = "assetmaps",
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@ -966,7 +1040,7 @@ static const AVClass imf_class = {
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const AVInputFormat ff_imf_demuxer = {
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.name = "imf",
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.long_name = NULL_IF_CONFIG_SMALL("IMF (Interoperable Master Format)"),
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.flags = AVFMT_EXPERIMENTAL,
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.flags = AVFMT_EXPERIMENTAL | AVFMT_NO_BYTE_SEEK,
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.flags_internal = FF_FMT_INIT_CLEANUP,
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.priv_class = &imf_class,
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.priv_data_size = sizeof(IMFContext),
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@ -974,4 +1048,5 @@ const AVInputFormat ff_imf_demuxer = {
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.read_header = imf_read_header,
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.read_packet = imf_read_packet,
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.read_close = imf_close,
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.read_seek2 = imf_seek,
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};
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