From 53a3748ed23136615e488dc463b91aa57c0e9ec6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20B=C5=93sch?= Date: Wed, 1 Aug 2012 18:39:46 +0200 Subject: [PATCH] ffmpeg: honor -ss and -t parameters with muxed subtitles. This patch fixes two things: - in case of subtitles, check_recording_time() is comparing the current PTS to the recording time (-t option, set to INT_MAX by default), so the -ss option needs to be taken into account. It is not required in do_{audio,video}_out() because this adjustment is set while polling the filtergraph (see poll_filters()). - It also adjusts the PTS sent to the encoder (and later transmitted to the muxer) so the TS in the output make sense and are not kept verbatim. Note: this only works for muxers honoring the PTS, such as lavf/matroskaenc. But for other such as the ASS muxer which just does a verbatim copy, or the SubRip muxer which doesn't write the TS in some cases, it will not work yet. --- ffmpeg.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/ffmpeg.c b/ffmpeg.c index f85d8e01a8..cc1b32fc79 100644 --- a/ffmpeg.c +++ b/ffmpeg.c @@ -1683,12 +1683,15 @@ static void do_subtitle_out(AVFormatContext *s, else nb = 1; + /* shift timestamp to honor -ss and make check_recording_time() work with -t */ + pts = av_rescale_q(pts, ist->st->time_base, AV_TIME_BASE_Q) + - output_files[ost->file_index]->start_time; for (i = 0; i < nb; i++) { - ost->sync_opts = av_rescale_q(pts, ist->st->time_base, enc->time_base); + ost->sync_opts = av_rescale_q(pts, AV_TIME_BASE_Q, enc->time_base); if (!check_recording_time(ost)) return; - sub->pts = av_rescale_q(pts, ist->st->time_base, AV_TIME_BASE_Q); + sub->pts = pts; // start_display_time is required to be 0 sub->pts += av_rescale_q(sub->start_display_time, (AVRational){ 1, 1000 }, AV_TIME_BASE_Q); sub->end_display_time -= sub->start_display_time;