December 2016 - ffmpeg-devel - lists.ffmpeg.org

[PATCH] avcodec/ac3dec: Check expacc
by Michael Niedermayer 04 Mar '22

04 Mar '22

Signed-off-by: Michael Niedermayer <michael(a)niedermayer.cc> --- libavcodec/ac3dec.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c index a95c204..499971a 100644 --- a/libavcodec/ac3dec.c +++ b/libavcodec/ac3dec.c @@ -426,6 +426,10 @@ static int decode_exponents(AC3DecodeContext *s, group_size = exp_strategy + (exp_strategy == EXP_D45); for (grp = 0, i = 0; grp < ngrps; grp++) { expacc = get_bits(gbc, 7); + if (expacc >= 125) { + av_log(s->avctx, AV_LOG_ERROR, "expacc %d is out-of-range\n", expacc); + return AVERROR_INVALIDDATA; + } dexp[i++] = ungroup_3_in_7_bits_tab[expacc][0]; dexp[i++] = ungroup_3_in_7_bits_tab[expacc][1]; dexp[i++] = ungroup_3_in_7_bits_tab[expacc][2]; -- 2.10.2

3 4

[PATCH] fate: remove "-v 0" from ffprobe tests.
by Nicolas George 24 Aug '20

24 Aug '20

The FATE scripts separate stdout from stderr. Having a first idea about what went wrong in the log file is more convenient. Signed-off-by: Nicolas George <george(a)nsup.org> --- tests/fate-run.sh | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tests/fate-run.sh b/tests/fate-run.sh index 3d58080..4b31b62 100755 --- a/tests/fate-run.sh +++ b/tests/fate-run.sh @@ -84,7 +84,7 @@ runecho(){ } probefmt(){ - run ffprobe${PROGSUF} -show_entries format=format_name -print_format default=nw=1:nk=1 -v 0 "$@" + run ffprobe${PROGSUF} -show_entries format=format_name -print_format default=nw=1:nk=1 "$@" } runlocal(){ @@ -93,24 +93,24 @@ runlocal(){ } probeframes(){ - run ffprobe${PROGSUF} -show_frames -v 0 "$@" + run ffprobe${PROGSUF} -show_frames "$@" } probechapters(){ - run ffprobe${PROGSUF} -show_chapters -v 0 "$@" + run ffprobe${PROGSUF} -show_chapters "$@" } probegaplessinfo(){ filename="$1" shift - run ffprobe${PROGSUF} -bitexact -select_streams a -show_entries format=start_time,duration:stream=index,start_pts,duration_ts -v 0 "$filename" "$@" + run ffprobe${PROGSUF} -bitexact -select_streams a -show_entries format=start_time,duration:stream=index,start_pts,duration_ts "$filename" "$@" pktfile1="${outdir}/${test}.pkts" framefile1="${outdir}/${test}.frames" cleanfiles="$cleanfiles $pktfile1 $framefile1" - run ffprobe${PROGSUF} -bitexact -select_streams a -of compact -count_packets -show_entries packet=pts,dts,duration:stream=nb_read_packets -v 0 "$filename" "$@" > "$pktfile1" + run ffprobe${PROGSUF} -bitexact -select_streams a -of compact -count_packets -show_entries packet=pts,dts,duration:stream=nb_read_packets "$filename" "$@" > "$pktfile1" head -n 8 "$pktfile1" tail -n 9 "$pktfile1" - run ffprobe${PROGSUF} -bitexact -select_streams a -of compact -count_frames -show_entries frame=pkt_pts,pkt_dts,best_effort_timestamp,pkt_duration,nb_samples:stream=nb_read_frames -v 0 "$filename" "$@" > "$framefile1" + run ffprobe${PROGSUF} -bitexact -select_streams a -of compact -count_frames -show_entries frame=pkt_pts,pkt_dts,best_effort_timestamp,pkt_duration,nb_samples:stream=nb_read_frames "$filename" "$@" > "$framefile1" head -n 8 "$framefile1" tail -n 9 "$framefile1" } @@ -306,10 +306,10 @@ concat(){ awk "{gsub(/%SRCFILE%/, \"$sample\"); print}" $template > $concatfile if [ "$mode" = "md5" ]; then - run ffprobe${PROGSUF} -bitexact -show_streams -show_packets -v 0 -fflags keepside -safe 0 $extra_args $concatfile | tr -d '\r' > $packetfile + run ffprobe${PROGSUF} -bitexact -show_streams -show_packets -fflags keepside -safe 0 $extra_args $concatfile | tr -d '\r' > $packetfile do_md5sum $packetfile else - run ffprobe${PROGSUF} -bitexact -show_streams -show_packets -v 0 -of compact=p=0:nk=1 -fflags keepside -safe 0 $extra_args $concatfile + run ffprobe${PROGSUF} -bitexact -show_streams -show_packets -of compact=p=0:nk=1 -fflags keepside -safe 0 $extra_args $concatfile fi } -- 2.8.1

2 4

[PATCH] lavf/matroskadec: Demux the PixelCrop* values
by Nic Wolfe 30 Mar '20

30 Mar '20

The Matroska spec defines PixelCropTop, PixelCropBottom, PixelCropLeft, and PixelCropRight elements: https://www.matroska.org/technical/specs/index.html This commit adds support for demuxing these values so that applications using libav* are able to use them when playing the stream. They're added to the AVStream's metadata if they are set to something non-zero. My official patch is base64 encoded and attached but I will also include the diff below for (hopefully) convenience. Thanks, Nic diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index d788232..72537df 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -139,6 +139,10 @@ typedef struct MatroskaTrackVideo { EbmlBin color_space; uint64_t stereo_mode; uint64_t alpha_mode; + uint64_t crop_bottom; + uint64_t crop_top; + uint64_t crop_left; + uint64_t crop_right; } MatroskaTrackVideo; typedef struct MatroskaTrackAudio { @@ -364,10 +368,10 @@ static const EbmlSyntax matroska_track_video[] = { { MATROSKA_ID_VIDEOPIXELHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo, pixel_height) }, { MATROSKA_ID_VIDEOCOLORSPACE, EBML_BIN, 0, offsetof(MatroskaTrackVideo, color_space) }, { MATROSKA_ID_VIDEOALPHAMODE, EBML_UINT, 0, offsetof(MatroskaTrackVideo, alpha_mode) }, - { MATROSKA_ID_VIDEOPIXELCROPB, EBML_NONE }, - { MATROSKA_ID_VIDEOPIXELCROPT, EBML_NONE }, - { MATROSKA_ID_VIDEOPIXELCROPL, EBML_NONE }, - { MATROSKA_ID_VIDEOPIXELCROPR, EBML_NONE }, + { MATROSKA_ID_VIDEOPIXELCROPB, EBML_UINT, 0, offsetof(MatroskaTrackVideo, crop_bottom) }, + { MATROSKA_ID_VIDEOPIXELCROPT, EBML_UINT, 0, offsetof(MatroskaTrackVideo, crop_top) }, + { MATROSKA_ID_VIDEOPIXELCROPL, EBML_UINT, 0, offsetof(MatroskaTrackVideo, crop_left) }, + { MATROSKA_ID_VIDEOPIXELCROPR, EBML_UINT, 0, offsetof(MatroskaTrackVideo, crop_right) }, { MATROSKA_ID_VIDEODISPLAYUNIT, EBML_NONE }, { MATROSKA_ID_VIDEOFLAGINTERLACED, EBML_NONE }, { MATROSKA_ID_VIDEOSTEREOMODE, EBML_UINT, 0, offsetof(MatroskaTrackVideo, stereo_mode), { .u = MATROSKA_VIDEO_STEREOMODE_TYPE_NB } }, @@ -2152,6 +2156,16 @@ static int matroska_parse_tracks(AVFormatContext *s) if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB) av_dict_set(&st->metadata, "stereo_mode", ff_matroska_video_stereo_mode[track->video.stereo_mode], 0); + /* export the matroska crop settings as metadata */ + if (track->video.crop_bottom != 0) + av_dict_set_int(&st->metadata, "crop_bottom", track->video.crop_bottom, 0); + if (track->video.crop_top != 0) + av_dict_set_int(&st->metadata, "crop_top", track->video.crop_top, 0); + if (track->video.crop_left != 0) + av_dict_set_int(&st->metadata, "crop_left", track->video.crop_left, 0); + if (track->video.crop_right != 0) + av_dict_set_int(&st->metadata, "crop_right", track->video.crop_right, 0); + /* export alpha mode flag as metadata tag */ if (track->video.alpha_mode) av_dict_set(&st->metadata, "alpha_mode", "1", 0);

5 7

[PATCH] avformat/avlanguage: deprecate av_convert_lang_to and make it internal
by James Almer 27 Nov '19

27 Nov '19

The header was never installed and the function is only used in libavformat Signed-off-by: James Almer <jamrial(a)gmail.com> --- libavformat/asfdec_f.c | 2 +- libavformat/asfdec_o.c | 2 +- libavformat/asfenc.c | 2 +- libavformat/avienc.c | 2 +- libavformat/avlanguage.c | 11 +++++++++-- libavformat/avlanguage.h | 7 +++++++ libavformat/matroskaenc.c | 2 +- 7 files changed, 21 insertions(+), 7 deletions(-) diff --git a/libavformat/asfdec_f.c b/libavformat/asfdec_f.c index 2c81b13..b973eff 100644 --- a/libavformat/asfdec_f.c +++ b/libavformat/asfdec_f.c @@ -912,7 +912,7 @@ static int asf_read_header(AVFormatContext *s) const char *rfc1766 = asf->stream_languages[asf->streams[i].stream_language_index]; if (rfc1766 && strlen(rfc1766) > 1) { const char primary_tag[3] = { rfc1766[0], rfc1766[1], '\0' }; // ignore country code if any - const char *iso6392 = av_convert_lang_to(primary_tag, + const char *iso6392 = ff_convert_lang_to(primary_tag, AV_LANG_ISO639_2_BIBL); if (iso6392) av_dict_set(&st->metadata, "language", iso6392, 0); diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c index 1c564a8..f8caf16 100644 --- a/libavformat/asfdec_o.c +++ b/libavformat/asfdec_o.c @@ -829,7 +829,7 @@ static void set_language(AVFormatContext *s, const char *rfc1766, AVDictionary * // language abbr should contain at least 2 chars if (rfc1766 && strlen(rfc1766) > 1) { const char primary_tag[3] = { rfc1766[0], rfc1766[1], '\0' }; // ignore country code if any - const char *iso6392 = av_convert_lang_to(primary_tag, + const char *iso6392 = ff_convert_lang_to(primary_tag, AV_LANG_ISO639_2_BIBL); if (iso6392) if (av_dict_set(met, "language", iso6392, 0) < 0) diff --git a/libavformat/asfenc.c b/libavformat/asfenc.c index cfa4fad..93ab167 100644 --- a/libavformat/asfenc.c +++ b/libavformat/asfenc.c @@ -431,7 +431,7 @@ static int asf_write_header1(AVFormatContext *s, int64_t file_size, entry = av_dict_get(s->streams[n]->metadata, "language", NULL, 0); if (entry) { - const char *iso6391lang = av_convert_lang_to(entry->value, AV_LANG_ISO639_1); + const char *iso6391lang = ff_convert_lang_to(entry->value, AV_LANG_ISO639_1); if (iso6391lang) { int i; for (i = 0; i < asf->nb_languages; i++) { diff --git a/libavformat/avienc.c b/libavformat/avienc.c index c908c21..59ad2b2 100644 --- a/libavformat/avienc.c +++ b/libavformat/avienc.c @@ -435,7 +435,7 @@ static int avi_write_header(AVFormatContext *s) } if (par->codec_id == AV_CODEC_ID_XSUB && (t = av_dict_get(s->streams[i]->metadata, "language", NULL, 0))) { - const char* langstr = av_convert_lang_to(t->value, AV_LANG_ISO639_1); + const char* langstr = ff_convert_lang_to(t->value, AV_LANG_ISO639_1); t = NULL; if (langstr) { char* str = av_asprintf("Subtitle - %s-xx;02", langstr); diff --git a/libavformat/avlanguage.c b/libavformat/avlanguage.c index 39f2560..f5d2ddf 100644 --- a/libavformat/avlanguage.c +++ b/libavformat/avlanguage.c @@ -733,7 +733,7 @@ static int lang_table_compare(const void *lhs, const void *rhs) return strcmp(lhs, ((const LangEntry *)rhs)->str); } -const char *av_convert_lang_to(const char *lang, enum AVLangCodespace target_codespace) +const char *ff_convert_lang_to(const char *lang, enum AVLangCodespace target_codespace) { int i; const LangEntry *entry = NULL; @@ -759,7 +759,14 @@ const char *av_convert_lang_to(const char *lang, enum AVLangCodespace target_cod entry = lang_table + entry->next_equivalent; if (target_codespace == AV_LANG_ISO639_2_TERM) - return av_convert_lang_to(lang, AV_LANG_ISO639_2_BIBL); + return ff_convert_lang_to(lang, AV_LANG_ISO639_2_BIBL); return NULL; } + +#if LIBAVFORMAT_VERSION_MAJOR < 58 +const char *av_convert_lang_to(const char *lang, enum AVLangCodespace target_codespace) +{ + return ff_convert_lang_to(lang, target_codespace); +} +#endif diff --git a/libavformat/avlanguage.h b/libavformat/avlanguage.h index 7fb8968..8b91b2a 100644 --- a/libavformat/avlanguage.h +++ b/libavformat/avlanguage.h @@ -21,6 +21,9 @@ #ifndef AVFORMAT_AVLANGUAGE_H #define AVFORMAT_AVLANGUAGE_H +#include "libavutil/attributes.h" +#include "libavformat/version.h" + /** * Known language codespaces */ @@ -34,6 +37,10 @@ enum AVLangCodespace { * Convert a language code to a target codespace. The source codespace is guessed. * @return NULL if the provided lang is null or invalid. */ +const char *ff_convert_lang_to(const char *lang, enum AVLangCodespace target_codespace); +#if LIBAVFORMAT_VERSION_MAJOR < 58 +attribute_deprecated const char *av_convert_lang_to(const char *lang, enum AVLangCodespace target_codespace); +#endif #endif /* AVFORMAT_AVLANGUAGE_H */ diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c index 4cd9878..2bf9b30 100644 --- a/libavformat/matroskaenc.c +++ b/libavformat/matroskaenc.c @@ -1257,7 +1257,7 @@ static int mkv_write_simpletag(AVIOContext *pb, AVDictionaryEntry *t) return AVERROR(ENOMEM); if ((p = strrchr(p, '-')) && - (lang = av_convert_lang_to(p + 1, AV_LANG_ISO639_2_BIBL))) + (lang = ff_convert_lang_to(p + 1, AV_LANG_ISO639_2_BIBL))) *p = 0; p = key; -- 2.8.1

3 5

[PATCH] lavfi: add realtime filter.
by Nicolas George 25 Oct '18

25 Oct '18

Similar to the -re option in ffmpeg that only works for input files. Can be used at any place in the filter graph. Signed-off-by: Nicolas George <george(a)nsup.org> --- Changelog | 1 + doc/filters.texi | 16 ++++++ libavfilter/Makefile | 2 + libavfilter/allfilters.c | 2 + libavfilter/f_realtime.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 151 insertions(+) create mode 100644 libavfilter/f_realtime.c diff --git a/Changelog b/Changelog index abaac19..1c8fe37 100644 --- a/Changelog +++ b/Changelog @@ -25,6 +25,7 @@ version <next>: - wve demuxer - zero-copy Intel QSV transcoding in ffmpeg - shuffleframes filter +- realtime filter version 2.8: diff --git a/doc/filters.texi b/doc/filters.texi index 5a35bde..141394c 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -13052,6 +13052,22 @@ following one, the permission might not be received as expected in that following filter. Inserting a @ref{format} or @ref{aformat} filter before the perms/aperms filter can avoid this problem. +@section realtime, arealtime + +Slow down filtering to match real time approximatively. + +These filters will pause the filtering for a variable amount of time to +match the output rate with the input timestamps. +They are similar to the @option{re} option to @code{ffmpeg}. + +They accept the following options: + +@table @option +@item limit +Time limit for the pauses. Any pause longer than that will be considered +a timestamp discontinuity and reset the timer. Default is 2 seconds. +@end table + @section select, aselect Select frames to pass in output. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index dd4f547..9c07d98 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -39,6 +39,7 @@ OBJS-$(CONFIG_ANULL_FILTER) += af_anull.o OBJS-$(CONFIG_APAD_FILTER) += af_apad.o OBJS-$(CONFIG_APERMS_FILTER) += f_perms.o OBJS-$(CONFIG_APHASER_FILTER) += af_aphaser.o generate_wave_table.o +OBJS-$(CONFIG_AREALTIME_FILTER) += f_realtime.o OBJS-$(CONFIG_ARESAMPLE_FILTER) += af_aresample.o OBJS-$(CONFIG_AREVERSE_FILTER) += f_reverse.o OBJS-$(CONFIG_ASELECT_FILTER) += f_select.o @@ -196,6 +197,7 @@ OBJS-$(CONFIG_PSNR_FILTER) += vf_psnr.o dualinput.o framesync. OBJS-$(CONFIG_PULLUP_FILTER) += vf_pullup.o OBJS-$(CONFIG_QP_FILTER) += vf_qp.o OBJS-$(CONFIG_RANDOM_FILTER) += vf_random.o +OBJS-$(CONFIG_REALTIME_FILTER) += f_realtime.o OBJS-$(CONFIG_REMOVEGRAIN_FILTER) += vf_removegrain.o OBJS-$(CONFIG_REMOVELOGO_FILTER) += bbox.o lswsutils.o lavfutils.o vf_removelogo.o OBJS-$(CONFIG_REPEATFIELDS_FILTER) += vf_repeatfields.o diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 8e363a0..239fbb5 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -61,6 +61,7 @@ void avfilter_register_all(void) REGISTER_FILTER(APAD, apad, af); REGISTER_FILTER(APERMS, aperms, af); REGISTER_FILTER(APHASER, aphaser, af); + REGISTER_FILTER(AREALTIME, arealtime, af); REGISTER_FILTER(ARESAMPLE, aresample, af); REGISTER_FILTER(AREVERSE, areverse, af); REGISTER_FILTER(ASELECT, aselect, af); @@ -217,6 +218,7 @@ void avfilter_register_all(void) REGISTER_FILTER(PULLUP, pullup, vf); REGISTER_FILTER(QP, qp, vf); REGISTER_FILTER(RANDOM, random, vf); + REGISTER_FILTER(REALTIME, realtime, vf); REGISTER_FILTER(REMOVEGRAIN, removegrain, vf); REGISTER_FILTER(REMOVELOGO, removelogo, vf); REGISTER_FILTER(REPEATFIELDS, repeatfields, vf); diff --git a/libavfilter/f_realtime.c b/libavfilter/f_realtime.c new file mode 100644 index 0000000..a50141c --- /dev/null +++ b/libavfilter/f_realtime.c @@ -0,0 +1,130 @@ +/* + * Copyright (c) 2015 Nicolas George + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public License + * as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with FFmpeg; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "libavutil/opt.h" +#include "libavutil/time.h" +#include "avfilter.h" +#include "internal.h" + +typedef struct RealtimeContext { + const AVClass *class; + int64_t delta; + int64_t limit; + unsigned inited; +} RealtimeContext; + +static int filter_frame(AVFilterLink *inlink, AVFrame *frame) +{ + AVFilterContext *ctx = inlink->dst; + RealtimeContext *s = ctx->priv; + + if (frame->pts != AV_NOPTS_VALUE) { + int64_t pts = av_rescale_q(frame->pts, inlink->time_base, AV_TIME_BASE_Q); + int64_t now = av_gettime_relative(); + int64_t sleep = pts - now + s->delta; + if (!s->inited) { + s->inited = 1; + sleep = 0; + s->delta = now - pts; + } + if (sleep > s->limit || sleep < -s->limit) { + av_log(ctx, AV_LOG_WARNING, + "time discontinuity detected: %"PRIi64" us, resetting\n", + sleep); + sleep = 0; + s->delta = now - pts; + } + if (sleep > 0) { + av_log(ctx, AV_LOG_DEBUG, "sleeping %"PRIi64" us\n", sleep); + av_usleep(sleep); + } + } + return ff_filter_frame(inlink->dst->outputs[0], frame); +} + +#define OFFSET(x) offsetof(RealtimeContext, x) +#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM +static const AVOption options[] = { + { "limit", "sleep time limit", OFFSET(limit), AV_OPT_TYPE_DURATION, { .i64 = 2000000 }, 0, INT64_MAX, FLAGS }, + { NULL } +}; + +#if CONFIG_REALTIME_FILTER +#define realtime_options options +AVFILTER_DEFINE_CLASS(realtime); + +static const AVFilterPad avfilter_vf_realtime_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad avfilter_vf_realtime_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + }, + { NULL } +}; + +AVFilter ff_vf_realtime = { + .name = "realtime", + .description = NULL_IF_CONFIG_SMALL("Slow down filtering to match realtime"), + .priv_size = sizeof(RealtimeContext), + .priv_class = &realtime_class, + .inputs = avfilter_vf_realtime_inputs, + .outputs = avfilter_vf_realtime_outputs, +}; +#endif /* CONFIG_REALTIME_FILTER */ + +#if CONFIG_AREALTIME_FILTER + +#define arealtime_options options +AVFILTER_DEFINE_CLASS(arealtime); + +static const AVFilterPad arealtime_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad arealtime_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + }, + { NULL } +}; + +AVFilter ff_af_arealtime = { + .name = "arealtime", + .description = NULL_IF_CONFIG_SMALL("Slow down filtering to match realtime"), + .priv_size = sizeof(RealtimeContext), + .priv_class = &arealtime_class, + .inputs = arealtime_inputs, + .outputs = arealtime_outputs, +}; +#endif /* CONFIG_AREALTIME_FILTER */ -- 2.6.1

4 8

Evolution of lavfi's design and API
by Nicolas George 07 Jun '18

07 Jun '18

[ CCing Anton, as most that is written here also apply to libav too, and this would be a good occasion to try a cross-fork cooperation; if that is not wanted, please let us know so we can drop the cc. ] 1. Problems with the current design 1.1. Mixed input-/output-driven model Currently, lavfi is designed to work in a mixed input-driven and output-driven model. That means the application needs sometimes to add input to buffersources and sometimes request output to buffersinks. This is a bit of a nuisance, because it requires the application to do it properly: adding input on the wrong input or requesting a frame on the wrong output will cause extra memory consumption or latency. With the libav API, it can not work at all since there is no mechanism to determine which input needs a frame in order to proceed. The libav API is clearly designed for a more output-driven implementation, with FIFOs anywhere to prevent input-driven frames to reach unready filters. Unfortunately, since it is impossible from the outside to guess what output will get a frame next, that can cause frames to accumulate anywhere in the filter graph, eating a lot of memory unnecessarily. FFmpeg's API has eliminated FIFOs in favour of queues in filters that need it, but these queues can not be controlled for unusual filter graphs with extreme needs. Also, there still is an implicit FIFO inside buffersink. 1.2. Recursive implementation All work in a filter graph is triggered by recursive invocations of the filters' methods. It makes debugging harder. It also can lead to large stack usage and makes frame- and filter-level multithreading harder to implement. It also prevents some diagnosis from working reliably. 1.3. EOF handling Currently, EOF is propagated only through the return value of the request_frame() method. That means it only works in an output-driven scheme. It also means that it has no timestamp attached to it; this is an issue for filters where the duration of the last frame is relevant, like vf_fps. 1.4. Latency Some filters need to know the timestamp of the next frame in order to know when the current frame will stop and be able to process it: overlay, fps are two examples. These filters will introduce a latency of one input frame that could otherwise be avoided. 1.5. Timestamps Some filters do not care about timestamps at all. Some check and have a proper handling of NOPTS values. Some filters just assume the frames will have timestamps, and possibly make extra assumptions on that: monotony, consistency, etc. That is an inconsistent mess. 1.6. Sparse streams There is a more severe instance of the latency issue when the input comes from an interleaved sparse stream: in that case, waiting for the next frame in order to find the end of the current one may require demuxing a large chunk of input, in turn provoking a lot of activity on other inputs of the graph. 2. Proposed API changes To fix/enhance all these issues, I believe a complete rethink of the scheduling design of the library is necessary. I propose the following changes. Note: some of these changes are not 100% related to the issues I raised, but looked like a good idea while thinking on an API rework. 2.1. AVFrame.duration Add a duration field to AVFrame; if set, it indicates the duration of the frame. Thus, it becomes unnecessary to wait for the next frame to know when the current frame stops, reducing the latency. Another solution would be to add a dedicated function on buffersrc to inject a timestamp for end or activity on a link. That would avoid the need of adding a field to AVFrame. 2.2. Add some fields to AVFilterLink AVFilterLink.pts: current timestamp of the link, i.e. end timestamp of the last forwarede frame, assuming the duration was correct. This is somewhat redundant with the fields in AVFrame, but can carry the information even when there is no actual frame. AVFilterLink.status: if not 0, gives the return status of trying to pass a frame on this link. The typical use would be EOF. 2.3. AVFilterLink.need_ts Add a field to AVFilterLink to specify that the output filter requires reliable timestamps on its input. More precisely, specify how reliable the timestamps need to be: is the duration necessary? do the timestamps need to be monotonic? continuous? For audio streams, consistency between timestamps and the number of samples may also be tested. For video streams, constant frame rate may be enforced, but I am not sure about this one. A "fixpts" filter should be provided to allow the user to tweak how the timestamps are fixed (change the timestamps to match the duration or change the duration to match the timestamps?). When no explicit filter is inserted, the framework should do the work of fixing them automatically. I am not sure whether that should be done directly or by automatically inserting the fixpts filter. The later solution is more elegant, but it requires more changes to the framework and the filters (because the correctness of the timestamps would need to be merged just like formats), so I am rather for the former. Note that for a lot of filters, the actual duration or end timestamp is not required, only a lower bound for it. For sparse interleaved streams, that is very relevant as we may not know the exact time for the next frame until we reach it, but we can know it is later than the other streams' timestamps minus the interleaving delta. 2.4. Build FIFOs directly in AVFilterLink Instead of automatically insert an additional filter like libav, handle the FIFO operation directly in the framework using fields in AVFilterLink. The main benefit is that the framework can examine the inside of the FIFOs to make scheduling decisions. It can also do so to provide the user with more accurate diagnostics. An extra benefit: the memory pool for the FIFOed frames can more easily be shared, across the whole filter graph or the whole application. Memory management becomes easier: just take a good heuristics (half the RAM?), no need to guess what FIFOs will actually need a lot of memory and what FIFOs are just there mostly useless. Last but not least, FIFOs now become potential thread communication / synchronization points, making filter-level multithreading easier. For audio streams, framing (i.e. ensuring all frame have an exact / minimum / maximum number of samples) can be merged with FIFOs. 2.5. Allow status change pseudo-frames inside FIFOs To propagate EOF and possibly other status changes (errors) in input-driven model, allow FIFOs to contain not only frames but also kind of pseudo-frames with a timestamp and metadata attached. Depending on the filters, these pseudo-frames may be directly passed to the filter's methods, or they may be interpreted by the framework to just change fields on the AVFilterLink structure. 2.6. Change the scheduling logic for filters From the outside of a filter with several outputs, it is usually not possible to guess what output will get a frame next. Requesting a frame on output #0 may cause activity on the filter graph that produce a frame on output #1 instead, or possibly on a completely different filter. Therefore, having a request_frame() method on all outputs seems pointless. Instead, use a global AVFilter.activate() method that causes the filter to do one step of work if it can. This method is called each time something is changed to the filter: new frame on input, output ready, status change. It returns as soon at it could do something, either producing output and/or consuming input, or nothing if nothing can be done. 2.7. Add fields to AVFilterLink for flow control. Add to AVFilterLinks a few field to help filters decide if they need to process something, and if relevant in what order. The most obvious idea would be AVFilterLink.frames_needed, counting how many frames are probably needed on a link before anything can be done. For example, with concat, after input has been consumed, the frames_needed fields on the current input are set according to the corresponding output. 2.8. Activate the filters iteratively Keep a global (per graph) priority queue of filters that are supposed to be ready and call the activate() method on them. 2.9. AVFrame.stream_id Add an integer (or pointer: intptr_t maybe?) field to AVFrame to allow passing frames related to distinct streams on the same link. That would allow to multiplex all outputs of a graph into a single output, making the application simpler. Not sure this is really useful or necessary: for the graph outputs, a convenience function iterating on all of them and returning the frame and the output index separately would do the trick too. 2.10. buffersrc.callback and buffersink.callback Add a callback on both buffersource and buffersink, called respectively when a frame is necessary on input and a frame has arrived on output. This allows pure input-driven and pure output-driven design to work. 2.11. Links groups Links that carry frames from related interleaved streams should be explicitly connected together so that the framework can use the information. The typical use would be to group all the links from buffersrc that come from the same interleaved input file. When a frame is passed on a link, all links in the same group(s) that are too late (according to an interleaving tolerance that can be set) are activated using a dummy frame. 2.12. FIFOs with compression and external storage All FIFOs should be able to off-load some of their memory requirements by either compressing the frames (using a lossless or optionally lossy codec) and/or storing them on mass storage. The options for that should be changeable globally or on a per-link basis. 2.13. AVFrame.owner Add a owner field (probably with type "AVObject", i.e. "void *" pointing to AVClass *) to AVFrame, and update it whenever the frame is passed from one filter to the other. That way, inconsistent ref/unref operations can be detected. Regards, -- Nicolas George

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[PATCH] mxfdec: fix NULL pointer dereference in mxf_read_packet_old
by Andreas Cadhalpun 05 Jun '18

05 Jun '18

Metadata streams have priv_data set to NULL. Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun(a)googlemail.com> --- libavformat/mxfdec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c index a1a79ce..2ad0c28 100644 --- a/libavformat/mxfdec.c +++ b/libavformat/mxfdec.c @@ -3135,7 +3135,7 @@ static int mxf_read_packet_old(AVFormatContext *s, AVPacket *pkt) if (mxf->nb_index_tables >= 1 && mxf->current_edit_unit < t->nb_ptses) { pkt->dts = mxf->current_edit_unit + t->first_dts; pkt->pts = t->ptses[mxf->current_edit_unit]; - } else if (track->intra_only) { + } else if (track && track->intra_only) { /* intra-only -> PTS = EditUnit. * let utils.c figure out DTS since it can be < PTS if low_delay = 0 (Sony IMX30) */ pkt->pts = mxf->current_edit_unit; -- 2.10.2

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FFmpeg at Chemnitzer Linux-Tage 2016
by Thilo Borgmann 31 Jan '18

31 Jan '18

Hi, I just registered FFmpeg for participation at the annual Chemnitzer Linux-Tage in 2016 (CLT) which takes place in Chemnitz, Germany from the 19th to the 20th March 2016. Like in the past years, we are planning to man a booth with some of our developers, give direct user support and receiving valuable feedback and non-working samples from our users. The registration is ongoing until early January and still has to be confirmed by the organization of the CLT. Currently, the following developers are registered for our booth: Carl Eugen Hoyos Thomas Volkert Thilo Borgmann For the last years, Alexander Strasser did all the administration and most of the organization. This year, I volunteered to handle all this stuff. If you're a developer and interested to participate at and/or visit our booth, we are happy to see you in Chemnitz! Feel free to contact me about anything regarding this. Like in the past years, chances are good that we can compensate travel and hotel costs for our booth staff developers. Once our registration is confirmed or declined, I will report back about it and if we are accepted for participation, I will also post on FFmpeg-user to announce our attendance. -Thilo

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order T-shirts
by Thomas Volkert 19 Dec '17

19 Dec '17

Hi, Some guys at the VDD asked for FFmpeg T-shirts. I'd like to do a new T-shirt order. The shirts could be given to multimedia devs who stop at one of our next booths. My idea is to order 25 shirts: 1*S 5*M 10*L 7*XL 2*XXL Last time we ordered 5 shirts and got a price of 22,50 Euro per shirt. So, we are talking about a maximum price of 562,50 Euro (excluding delivery costs). If you like or don't like this idea, feel free to leave a comment here. Best regards, Thomas.

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[PATCH] avcodec: add properties for lossless to AVCodecParameters
by Michael Niedermayer 13 Dec '17

13 Dec '17

Fixes Ticket5467 Signed-off-by: Michael Niedermayer <michael(a)niedermayer.cc> --- libavcodec/avcodec.h | 4 ++++ libavcodec/utils.c | 2 ++ 2 files changed, 6 insertions(+) diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h index 3813a0a..1db2e0f 100644 --- a/libavcodec/avcodec.h +++ b/libavcodec/avcodec.h @@ -4050,6 +4050,10 @@ typedef struct AVCodecParameters { * Audio only. Number of samples to skip after a discontinuity. */ int seek_preroll; + + /** Properties, like FF_CODEC_PROPERTY_LOSSLESS. + */ + int properties; } AVCodecParameters; /** diff --git a/libavcodec/utils.c b/libavcodec/utils.c index e6609ef..8638bc2 100644 --- a/libavcodec/utils.c +++ b/libavcodec/utils.c @@ -4076,6 +4076,7 @@ int avcodec_parameters_from_context(AVCodecParameters *par, par->bits_per_raw_sample = codec->bits_per_raw_sample; par->profile = codec->profile; par->level = codec->level; + par->properties = codec->properties; switch (par->codec_type) { case AVMEDIA_TYPE_VIDEO: @@ -4130,6 +4131,7 @@ int avcodec_parameters_to_context(AVCodecContext *codec, codec->bits_per_raw_sample = par->bits_per_raw_sample; codec->profile = par->profile; codec->level = par->level; + codec->properties = par->properties; switch (par->codec_type) { case AVMEDIA_TYPE_VIDEO: -- 1.7.9.5

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