From 811bd0784679dfcb4ed02043a37c92f9df10500e Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Sat, 15 Jun 2013 09:59:40 +0200 Subject: avconv: make input -ss accurate when transcoding Insert (a)trim filters on the corresponding inputs, so the extra frames are decoded and discarded. --- Changelog | 3 +++ avconv.h | 3 +++ avconv_filter.c | 54 +++++++++++++++++++++++++++++++++++++++--------------- avconv_opt.c | 6 ++++++ doc/avconv.texi | 18 +++++++++++++++--- 5 files changed, 66 insertions(+), 18 deletions(-) diff --git a/Changelog b/Changelog index 61110e901b..3b1d01e0b1 100644 --- a/Changelog +++ b/Changelog @@ -27,6 +27,9 @@ version 10: - WavPack encoding through libwavpack - Added the -n parameter to avconv - RTMP seek support +- when transcoding with avconv (i.e. not streamcopying), -ss is now accurate + even when used as an input option. Previous behavior can be restored with + the -noaccurate_seek option. version 9: diff --git a/avconv.h b/avconv.h index 1244d86ec3..2143c0fc79 100644 --- a/avconv.h +++ b/avconv.h @@ -88,6 +88,7 @@ typedef struct OptionsContext { /* input options */ int64_t input_ts_offset; int rate_emu; + int accurate_seek; SpecifierOpt *ts_scale; int nb_ts_scale; @@ -237,9 +238,11 @@ typedef struct InputFile { int eagain; /* true if last read attempt returned EAGAIN */ int ist_index; /* index of first stream in ist_table */ int64_t ts_offset; + int64_t start_time; /* user-specified start time in AV_TIME_BASE or AV_NOPTS_VALUE */ int nb_streams; /* number of stream that avconv is aware of; may be different from ctx.nb_streams if new streams appear during av_read_frame() */ int rate_emu; + int accurate_seek; #if HAVE_PTHREADS pthread_t thread; /* thread reading from this file */ diff --git a/avconv_filter.c b/avconv_filter.c index 0e276506f9..704a1b09b7 100644 --- a/avconv_filter.c +++ b/avconv_filter.c @@ -173,17 +173,18 @@ static void init_input_filter(FilterGraph *fg, AVFilterInOut *in) ist->filters[ist->nb_filters - 1] = fg->inputs[fg->nb_inputs - 1]; } -static int insert_trim(OutputStream *ost, AVFilterContext **last_filter, int *pad_idx) +static int insert_trim(int64_t start_time, int64_t duration, + AVFilterContext **last_filter, int *pad_idx, + const char *filter_name) { - OutputFile *of = output_files[ost->file_index]; AVFilterGraph *graph = (*last_filter)->graph; AVFilterContext *ctx; const AVFilter *trim; - const char *name = ost->st->codec->codec_type == AVMEDIA_TYPE_VIDEO ? "trim" : "atrim"; - char filter_name[128]; + enum AVMediaType type = avfilter_pad_get_type((*last_filter)->output_pads, *pad_idx); + const char *name = (type == AVMEDIA_TYPE_VIDEO) ? "trim" : "atrim"; int ret = 0; - if (of->recording_time == INT64_MAX && of->start_time == AV_NOPTS_VALUE) + if (duration == INT64_MAX && start_time == AV_NOPTS_VALUE) return 0; trim = avfilter_get_by_name(name); @@ -193,18 +194,16 @@ static int insert_trim(OutputStream *ost, AVFilterContext **last_filter, int *pa return AVERROR_FILTER_NOT_FOUND; } - snprintf(filter_name, sizeof(filter_name), "%s for output stream %d:%d", - name, ost->file_index, ost->index); ctx = avfilter_graph_alloc_filter(graph, trim, filter_name); if (!ctx) return AVERROR(ENOMEM); - if (of->recording_time != INT64_MAX) { - ret = av_opt_set_double(ctx, "duration", (double)of->recording_time / 1e6, + if (duration != INT64_MAX) { + ret = av_opt_set_double(ctx, "duration", (double)duration / 1e6, AV_OPT_SEARCH_CHILDREN); } - if (ret >= 0 && of->start_time != AV_NOPTS_VALUE) { - ret = av_opt_set_double(ctx, "start", (double)of->start_time / 1e6, + if (ret >= 0 && start_time != AV_NOPTS_VALUE) { + ret = av_opt_set_double(ctx, "start", (double)start_time / 1e6, AV_OPT_SEARCH_CHILDREN); } if (ret < 0) { @@ -229,6 +228,7 @@ static int configure_output_video_filter(FilterGraph *fg, OutputFilter *ofilter, { char *pix_fmts; OutputStream *ost = ofilter->ost; + OutputFile *of = output_files[ost->file_index]; AVCodecContext *codec = ost->st->codec; AVFilterContext *last_filter = out->filter_ctx; int pad_idx = out->pad_idx; @@ -299,7 +299,10 @@ static int configure_output_video_filter(FilterGraph *fg, OutputFilter *ofilter, pad_idx = 0; } - ret = insert_trim(ost, &last_filter, &pad_idx); + snprintf(name, sizeof(name), "trim for output stream %d:%d", + ost->file_index, ost->index); + ret = insert_trim(of->start_time, of->recording_time, + &last_filter, &pad_idx, name); if (ret < 0) return ret; @@ -313,6 +316,7 @@ static int configure_output_video_filter(FilterGraph *fg, OutputFilter *ofilter, static int configure_output_audio_filter(FilterGraph *fg, OutputFilter *ofilter, AVFilterInOut *out) { OutputStream *ost = ofilter->ost; + OutputFile *of = output_files[ost->file_index]; AVCodecContext *codec = ost->st->codec; AVFilterContext *last_filter = out->filter_ctx; int pad_idx = out->pad_idx; @@ -370,7 +374,10 @@ static int configure_output_audio_filter(FilterGraph *fg, OutputFilter *ofilter, pad_idx = 0; } - ret = insert_trim(ost, &last_filter, &pad_idx); + snprintf(name, sizeof(name), "trim for output stream %d:%d", + ost->file_index, ost->index); + ret = insert_trim(of->start_time, of->recording_time, + &last_filter, &pad_idx, name); if (ret < 0) return ret; @@ -415,11 +422,12 @@ static int configure_input_video_filter(FilterGraph *fg, InputFilter *ifilter, AVFilterContext *last_filter; const AVFilter *buffer_filt = avfilter_get_by_name("buffer"); InputStream *ist = ifilter->ist; + InputFile *f = input_files[ist->file_index]; AVRational tb = ist->framerate.num ? av_inv_q(ist->framerate) : ist->st->time_base; AVRational sar; char args[255], name[255]; - int ret; + int ret, pad_idx = 0; sar = ist->st->sample_aspect_ratio.num ? ist->st->sample_aspect_ratio : @@ -452,6 +460,13 @@ static int configure_input_video_filter(FilterGraph *fg, InputFilter *ifilter, last_filter = setpts; } + snprintf(name, sizeof(name), "trim for input stream %d:%d", + ist->file_index, ist->st->index); + ret = insert_trim(((f->start_time == AV_NOPTS_VALUE) || !f->accurate_seek) ? + AV_NOPTS_VALUE : 0, INT64_MAX, &last_filter, &pad_idx, name); + if (ret < 0) + return ret; + if ((ret = avfilter_link(last_filter, 0, in->filter_ctx, in->pad_idx)) < 0) return ret; return 0; @@ -463,8 +478,9 @@ static int configure_input_audio_filter(FilterGraph *fg, InputFilter *ifilter, AVFilterContext *last_filter; const AVFilter *abuffer_filt = avfilter_get_by_name("abuffer"); InputStream *ist = ifilter->ist; + InputFile *f = input_files[ist->file_index]; char args[255], name[255]; - int ret; + int ret, pad_idx = 0; snprintf(args, sizeof(args), "time_base=%d/%d:sample_rate=%d:sample_fmt=%s" ":channel_layout=0x%"PRIx64, @@ -530,6 +546,14 @@ static int configure_input_audio_filter(FilterGraph *fg, InputFilter *ifilter, last_filter = volume; } + + snprintf(name, sizeof(name), "trim for input stream %d:%d", + ist->file_index, ist->st->index); + ret = insert_trim(((f->start_time == AV_NOPTS_VALUE) || !f->accurate_seek) ? + AV_NOPTS_VALUE : 0, INT64_MAX, &last_filter, &pad_idx, name); + if (ret < 0) + return ret; + if ((ret = avfilter_link(last_filter, 0, in->filter_ctx, in->pad_idx)) < 0) return ret; diff --git a/avconv_opt.c b/avconv_opt.c index c8d917638b..f14d7f1c62 100644 --- a/avconv_opt.c +++ b/avconv_opt.c @@ -117,6 +117,7 @@ static void init_options(OptionsContext *o) o->recording_time = INT64_MAX; o->limit_filesize = UINT64_MAX; o->chapters_input_file = INT_MAX; + o->accurate_seek = 1; } /* return a copy of the input with the stream specifiers removed from the keys */ @@ -687,9 +688,11 @@ static int open_input_file(OptionsContext *o, const char *filename) f->ctx = ic; f->ist_index = nb_input_streams - ic->nb_streams; + f->start_time = o->start_time; f->ts_offset = o->input_ts_offset - (copy_ts ? 0 : timestamp); f->nb_streams = ic->nb_streams; f->rate_emu = o->rate_emu; + f->accurate_seek = o->accurate_seek; /* check if all codec options have been used */ unused_opts = strip_specifiers(o->g->codec_opts); @@ -2151,6 +2154,9 @@ const OptionDef options[] = { { "ss", HAS_ARG | OPT_TIME | OPT_OFFSET | OPT_INPUT | OPT_OUTPUT, { .off = OFFSET(start_time) }, "set the start time offset", "time_off" }, + { "accurate_seek", OPT_BOOL | OPT_OFFSET | OPT_EXPERT | + OPT_INPUT, { .off = OFFSET(accurate_seek) }, + "enable/disable accurate seeking with -ss" }, { "itsoffset", HAS_ARG | OPT_TIME | OPT_OFFSET | OPT_EXPERT | OPT_INPUT, { .off = OFFSET(input_ts_offset) }, "set the input ts offset", "time_off" }, diff --git a/doc/avconv.texi b/doc/avconv.texi index 940c18896b..7e9b77e41d 100644 --- a/doc/avconv.texi +++ b/doc/avconv.texi @@ -265,9 +265,15 @@ Set the file size limit. @item -ss @var{position} (@emph{input/output}) When used as an input option (before @code{-i}), seeks in this input file to -@var{position}. When used as an output option (before an output filename), -decodes but discards input until the timestamps reach @var{position}. This is -slower, but more accurate. +@var{position}. Note the in most formats it is not possible to seek exactly, so +@command{avconv} will seek to the closest seek point before @var{position}. +When transcoding and @option{-accurate_seek} is enabled (the default), this +extra segment between the seek point and @var{position} will be decoded and +discarded. When doing stream copy or when @option{-noaccurate_seek} is used, it +will be preserved. + +When used as an output option (before an output filename), decodes but discards +input until the timestamps reach @var{position}. @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form. @@ -834,6 +840,12 @@ This option is similar to @option{-filter_complex}, the only difference is that its argument is the name of the file from which a complex filtergraph description is to be read. +@item -accurate_seek (@emph{input}) +This option enables or disables accurate seeking in input files with the +@option{-ss} option. It is enabled by default, so seeking is accurate when +transcoding. Use @option{-noaccurate_seek} to disable it, which may be useful +e.g. when copying some streams and transcoding the others. + @end table @c man end OPTIONS -- cgit v1.2.3