From d1a2cd1e139dc87930bd0fd25e9cc30e1545deef Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Fri, 21 Jul 2023 15:20:21 +0200 Subject: fftools/ffmpeg_enc: factor out setting encoder timebase Mainly this fixes handling special values of -enc_time_base ('demux' or 'filter') for audio. It also prints a warning if -enc_time_base is specified for subtitles, instead of ignoring it silently (current subtitle encoding API only works with AV_TIME_BASE_Q). --- fftools/ffmpeg_enc.c | 154 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 93 insertions(+), 61 deletions(-) (limited to 'fftools') diff --git a/fftools/ffmpeg_enc.c b/fftools/ffmpeg_enc.c index 3c9fdd3237..c4874b4d78 100644 --- a/fftools/ffmpeg_enc.c +++ b/fftools/ffmpeg_enc.c @@ -190,6 +190,93 @@ static int set_encoder_id(OutputFile *of, OutputStream *ost) return 0; } +static int enc_choose_timebase(OutputStream *ost, AVFrame *frame) +{ + const OutputFile *of = output_files[ost->file_index]; + AVCodecContext *enc = ost->enc_ctx; + AVRational tb = (AVRational){ 0, 0 }; + AVRational fr; + FrameData *fd; + + if (ost->type == AVMEDIA_TYPE_SUBTITLE) { + if (ost->enc_timebase.num) + av_log(ost, AV_LOG_WARNING, + "-enc_time_base not supported for subtitles, ignoring\n"); + enc->time_base = AV_TIME_BASE_Q; + return 0; + } + + fd = frame_data(frame); + + // apply -enc_time_base + if (ost->enc_timebase.num == ENC_TIME_BASE_DEMUX && + (fd->dec.tb.num <= 0 || fd->dec.tb.den <= 0)) { + av_log(ost, AV_LOG_ERROR, + "Demuxing timebase not available - cannot use it for encoding\n"); + return AVERROR(EINVAL); + } + + switch (ost->enc_timebase.num) { + case 0: break; + case ENC_TIME_BASE_DEMUX: tb = fd->dec.tb; break; + case ENC_TIME_BASE_FILTER: tb = frame->time_base; break; + default: tb = ost->enc_timebase; break; + } + + if (ost->type == AVMEDIA_TYPE_AUDIO) { + enc->time_base = tb.num ? tb : (AVRational){ 1, frame->sample_rate }; + return 0; + } + + fr = ost->frame_rate; + if (!fr.num) + fr = fd->frame_rate_filter; + if (!fr.num && !ost->max_frame_rate.num) { + fr = (AVRational){25, 1}; + av_log(ost, AV_LOG_WARNING, + "No information " + "about the input framerate is available. Falling " + "back to a default value of 25fps. Use the -r option " + "if you want a different framerate.\n"); + } + + if (ost->max_frame_rate.num && + (av_q2d(fr) > av_q2d(ost->max_frame_rate) || + !fr.den)) + fr = ost->max_frame_rate; + + if (enc->codec->supported_framerates && !ost->force_fps) { + int idx = av_find_nearest_q_idx(fr, enc->codec->supported_framerates); + fr = enc->codec->supported_framerates[idx]; + } + // reduce frame rate for mpeg4 to be within the spec limits + if (enc->codec_id == AV_CODEC_ID_MPEG4) { + av_reduce(&fr.num, &fr.den, + fr.num, fr.den, 65535); + } + + if (av_q2d(fr) > 1e3 && ost->vsync_method != VSYNC_PASSTHROUGH && + (ost->vsync_method == VSYNC_CFR || ost->vsync_method == VSYNC_VSCFR || + (ost->vsync_method == VSYNC_AUTO && !(of->format->flags & AVFMT_VARIABLE_FPS)))){ + av_log(ost, AV_LOG_WARNING, "Frame rate very high for a muxer not efficiently supporting it.\n" + "Please consider specifying a lower framerate, a different muxer or " + "setting vsync/fps_mode to vfr\n"); + } + + enc->framerate = fr; + + ost->st->avg_frame_rate = fr; + + if (!(tb.num > 0 && tb.den > 0)) + tb = av_inv_q(fr); + if (!(tb.num > 0 && tb.den > 0)) + tb = frame->time_base; + + enc->time_base = tb; + + return 0; +} + int enc_open(OutputStream *ost, AVFrame *frame) { InputStream *ist = ost->ist; @@ -221,6 +308,12 @@ int enc_open(OutputStream *ost, AVFrame *frame) dec_ctx = ist->dec_ctx; } + ret = enc_choose_timebase(ost, frame); + if (ret < 0) { + av_log(ost, AV_LOG_ERROR, "Could not choose a time base for encoding\n"); + return AVERROR(EINVAL); + } + switch (enc_ctx->codec_type) { case AVMEDIA_TYPE_AUDIO: enc_ctx->sample_fmt = frame->format; @@ -234,65 +327,9 @@ int enc_open(OutputStream *ost, AVFrame *frame) else enc_ctx->bits_per_raw_sample = FFMIN(fd->bits_per_raw_sample, av_get_bytes_per_sample(enc_ctx->sample_fmt) << 3); - - enc_ctx->time_base = ost->enc_timebase.num > 0 ? ost->enc_timebase : - av_make_q(1, enc_ctx->sample_rate); break; case AVMEDIA_TYPE_VIDEO: { - AVRational fr = ost->frame_rate; - - if (!fr.num) - fr = fd->frame_rate_filter; - if (!fr.num && !ost->max_frame_rate.num) { - fr = (AVRational){25, 1}; - av_log(ost, AV_LOG_WARNING, - "No information " - "about the input framerate is available. Falling " - "back to a default value of 25fps. Use the -r option " - "if you want a different framerate.\n"); - } - - if (ost->max_frame_rate.num && - (av_q2d(fr) > av_q2d(ost->max_frame_rate) || - !fr.den)) - fr = ost->max_frame_rate; - - if (enc->supported_framerates && !ost->force_fps) { - int idx = av_find_nearest_q_idx(fr, enc->supported_framerates); - fr = enc->supported_framerates[idx]; - } - // reduce frame rate for mpeg4 to be within the spec limits - if (enc_ctx->codec_id == AV_CODEC_ID_MPEG4) { - av_reduce(&fr.num, &fr.den, - fr.num, fr.den, 65535); - } - - if (ost->enc_timebase.num == ENC_TIME_BASE_DEMUX) { - if (fd->dec.tb.num <= 0 || fd->dec.tb.den <= 0) { - av_log(ost, AV_LOG_ERROR, - "Demuxing timebase not available - cannot use it for encoding\n"); - return AVERROR(EINVAL); - } - - enc_ctx->time_base = fd->dec.tb; - } else if (ost->enc_timebase.num == ENC_TIME_BASE_FILTER) { - enc_ctx->time_base = frame->time_base; - } else { - enc_ctx->time_base = ost->enc_timebase.num > 0 ? ost->enc_timebase : - av_inv_q(fr); - } - - if (!(enc_ctx->time_base.num && enc_ctx->time_base.den)) - enc_ctx->time_base = frame->time_base; - if ( av_q2d(enc_ctx->time_base) < 0.001 && ost->vsync_method != VSYNC_PASSTHROUGH - && (ost->vsync_method == VSYNC_CFR || ost->vsync_method == VSYNC_VSCFR || - (ost->vsync_method == VSYNC_AUTO && !(of->format->flags & AVFMT_VARIABLE_FPS)))){ - av_log(ost, AV_LOG_WARNING, "Frame rate very high for a muxer not efficiently supporting it.\n" - "Please consider specifying a lower framerate, a different muxer or " - "setting vsync/fps_mode to vfr\n"); - } - enc_ctx->width = frame->width; enc_ctx->height = frame->height; enc_ctx->sample_aspect_ratio = ost->st->sample_aspect_ratio = @@ -314,10 +351,6 @@ int enc_open(OutputStream *ost, AVFrame *frame) enc_ctx->colorspace = frame->colorspace; enc_ctx->chroma_sample_location = frame->chroma_location; - enc_ctx->framerate = fr; - - ost->st->avg_frame_rate = fr; - // Field order: autodetection if (enc_ctx->flags & (AV_CODEC_FLAG_INTERLACED_DCT | AV_CODEC_FLAG_INTERLACED_ME) && ost->top_field_first >= 0) @@ -344,7 +377,6 @@ int enc_open(OutputStream *ost, AVFrame *frame) break; } case AVMEDIA_TYPE_SUBTITLE: - enc_ctx->time_base = AV_TIME_BASE_Q; if (!enc_ctx->width) { enc_ctx->width = ost->ist->par->width; enc_ctx->height = ost->ist->par->height; -- cgit v1.2.3