diff options
Diffstat (limited to 'fftools')
| -rw-r--r-- | fftools/ffmpeg.c | 98 | ||||
| -rw-r--r-- | fftools/ffmpeg.h | 8 | ||||
| -rw-r--r-- | fftools/ffmpeg_demux.c | 6 |
3 files changed, 89 insertions, 23 deletions
diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c index 8829a163e0..8dcc70e879 100644 --- a/fftools/ffmpeg.c +++ b/fftools/ffmpeg.c @@ -881,6 +881,85 @@ static int send_frame_to_filters(InputStream *ist, AVFrame *decoded_frame) return ret; } +static AVRational audio_samplerate_update(InputStream *ist, const AVFrame *frame) +{ + const int prev = ist->last_frame_tb.den; + const int sr = frame->sample_rate; + + AVRational tb_new; + int64_t gcd; + + if (frame->sample_rate == ist->last_frame_sample_rate) + goto finish; + + gcd = av_gcd(prev, sr); + + if (prev / gcd >= INT_MAX / sr) { + av_log(ist, AV_LOG_WARNING, + "Audio timestamps cannot be represented exactly after " + "sample rate change: %d -> %d\n", prev, sr); + + // LCM of 192000, 44100, allows to represent all common samplerates + tb_new = (AVRational){ 1, 28224000 }; + } else + tb_new = (AVRational){ 1, prev / gcd * sr }; + + // keep the frame timebase if it is strictly better than + // the samplerate-defined one + if (frame->time_base.num == 1 && frame->time_base.den > tb_new.den && + !(frame->time_base.den % tb_new.den)) + tb_new = frame->time_base; + + if (ist->last_frame_pts != AV_NOPTS_VALUE) + ist->last_frame_pts = av_rescale_q(ist->last_frame_pts, + ist->last_frame_tb, tb_new); + ist->last_frame_duration_est = av_rescale_q(ist->last_frame_duration_est, + ist->last_frame_tb, tb_new); + + ist->last_frame_tb = tb_new; + ist->last_frame_sample_rate = frame->sample_rate; + +finish: + return ist->last_frame_tb; +} + +static void audio_ts_process(InputStream *ist, AVFrame *frame) +{ + AVRational tb_filter = (AVRational){1, frame->sample_rate}; + AVRational tb; + int64_t pts_pred; + + // on samplerate change, choose a new internal timebase for timestamp + // generation that can represent timestamps from all the samplerates + // seen so far + tb = audio_samplerate_update(ist, frame); + pts_pred = ist->last_frame_pts == AV_NOPTS_VALUE ? 0 : + ist->last_frame_pts + ist->last_frame_duration_est; + + if (frame->pts == AV_NOPTS_VALUE) { + frame->pts = pts_pred; + frame->time_base = tb; + } else if (ist->last_frame_pts != AV_NOPTS_VALUE && + frame->pts > av_rescale_q_rnd(pts_pred, tb, frame->time_base, + AV_ROUND_UP)) { + // there was a gap in timestamps, reset conversion state + ist->filter_in_rescale_delta_last = AV_NOPTS_VALUE; + } + + frame->pts = av_rescale_delta(frame->time_base, frame->pts, + tb, frame->nb_samples, + &ist->filter_in_rescale_delta_last, tb); + + ist->last_frame_pts = frame->pts; + ist->last_frame_duration_est = av_rescale_q(frame->nb_samples, + tb_filter, tb); + + // finally convert to filtering timebase + frame->pts = av_rescale_q(frame->pts, tb, tb_filter); + frame->duration = frame->nb_samples; + frame->time_base = tb_filter; +} + static int decode_audio(InputStream *ist, AVPacket *pkt, int *got_output, int *decode_failed) { @@ -910,23 +989,7 @@ static int decode_audio(InputStream *ist, AVPacket *pkt, int *got_output, ist->next_dts += ((int64_t)AV_TIME_BASE * decoded_frame->nb_samples) / decoded_frame->sample_rate; - if (decoded_frame->pts == AV_NOPTS_VALUE) { - decoded_frame->pts = ist->dts; - decoded_frame->time_base = AV_TIME_BASE_Q; - } - if (pkt && pkt->duration && ist->prev_pkt_pts != AV_NOPTS_VALUE && - pkt->pts != AV_NOPTS_VALUE && pkt->pts - ist->prev_pkt_pts > pkt->duration) - ist->filter_in_rescale_delta_last = AV_NOPTS_VALUE; - if (pkt) - ist->prev_pkt_pts = pkt->pts; - if (decoded_frame->pts != AV_NOPTS_VALUE) { - AVRational tb_filter = (AVRational){1, decoded_frame->sample_rate}; - decoded_frame->pts = av_rescale_delta(decoded_frame->time_base, decoded_frame->pts, - tb_filter, decoded_frame->nb_samples, - &ist->filter_in_rescale_delta_last, - tb_filter); - decoded_frame->time_base = tb_filter; - } + audio_ts_process(ist, decoded_frame); ist->nb_samples = decoded_frame->nb_samples; err = send_frame_to_filters(ist, decoded_frame); @@ -1076,6 +1139,7 @@ static int decode_video(InputStream *ist, AVPacket *pkt, int *got_output, int64_ // update timestamp history ist->last_frame_duration_est = video_duration_estimate(ist, decoded_frame); ist->last_frame_pts = decoded_frame->pts; + ist->last_frame_tb = decoded_frame->time_base; if (debug_ts) { av_log(ist, AV_LOG_INFO, diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h index c07a1b86b6..c4abf89b58 100644 --- a/fftools/ffmpeg.h +++ b/fftools/ffmpeg.h @@ -359,7 +359,6 @@ typedef struct InputStream { AVRational framerate_guessed; - int64_t prev_pkt_pts; int64_t start; /* time when read started */ /* predicted dts of the next packet read for this stream or (when there are * several frames in a packet) of the next frame in current packet (in AV_TIME_BASE units) */ @@ -371,10 +370,13 @@ typedef struct InputStream { int64_t next_pts; int64_t pts; ///< current pts of the decoded frame (in AV_TIME_BASE units) - // pts/estimated duration of the last decoded video frame - // in decoder timebase + // pts/estimated duration of the last decoded frame + // * in decoder timebase for video, + // * in last_frame_tb (may change during decoding) for audio int64_t last_frame_pts; int64_t last_frame_duration_est; + AVRational last_frame_tb; + int last_frame_sample_rate; int wrap_correction_done; diff --git a/fftools/ffmpeg_demux.c b/fftools/ffmpeg_demux.c index 5afb3ff2c8..f8d95d1de6 100644 --- a/fftools/ffmpeg_demux.c +++ b/fftools/ffmpeg_demux.c @@ -864,7 +864,9 @@ static void add_input_streams(const OptionsContext *o, Demuxer *d) } ist->filter_in_rescale_delta_last = AV_NOPTS_VALUE; - ist->prev_pkt_pts = AV_NOPTS_VALUE; + + ist->last_frame_pts = AV_NOPTS_VALUE; + ist->last_frame_tb = (AVRational){ 1, 1 }; ist->dec_ctx = avcodec_alloc_context3(ist->dec); if (!ist->dec_ctx) @@ -905,8 +907,6 @@ static void add_input_streams(const OptionsContext *o, Demuxer *d) ist->framerate_guessed = av_guess_frame_rate(ic, st, NULL); - ist->last_frame_pts = AV_NOPTS_VALUE; - break; case AVMEDIA_TYPE_AUDIO: { int guess_layout_max = INT_MAX; |