[FFmpeg-devel] [PATCH 7/8] fftools/ffmpeg_demux: implement -bsf for input
Anton Khirnov
anton at khirnov.net
Fri Jan 5 18:42:50 EET 2024
Previously bitstream filters could only be applied right before muxing,
this allows to apply them right after demuxing.
---
Changelog | 1 +
doc/ffmpeg.texi | 22 +++--
fftools/ffmpeg_demux.c | 139 ++++++++++++++++++++++++++++----
fftools/ffmpeg_opt.c | 2 +-
tests/fate/ffmpeg.mak | 5 ++
tests/ref/fate/ffmpeg-bsf-input | 18 +++++
6 files changed, 164 insertions(+), 23 deletions(-)
create mode 100644 tests/ref/fate/ffmpeg-bsf-input
diff --git a/Changelog b/Changelog
index 5b2899d05b..f8191d88c7 100644
--- a/Changelog
+++ b/Changelog
@@ -18,6 +18,7 @@ version <next>:
- lavu/eval: introduce randomi() function in expressions
- VVC decoder
- fsync filter
+- ffmpeg CLI -bsf option may now be used for input as well as output
version 6.1:
- libaribcaption decoder
diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index d75517b443..59f7badcb6 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -2093,26 +2093,34 @@ an output mpegts file:
ffmpeg -i inurl -streamid 0:33 -streamid 1:36 out.ts
@end example
- at item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
-Apply bitstream filters to matching streams.
+ at item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{input/output,per-stream})
+Apply bitstream filters to matching streams. The filters are applied to each
+packet as it is received from the demuxer (when used as an input option) or
+before it is sent to the muxer (when used as an output option).
@var{bitstream_filters} is a comma-separated list of bitstream filter
-specifications. The specified bitstream filters are applied to coded packets in
-the order they are written in. Each bitstream filter specification is of the
-form
+specifications, each of the form
@example
@var{filter}[=@var{optname0}=@var{optval0}:@var{optname1}=@var{optval1}:...]
@end example
Any of the ',=:' characters that are to be a part of an option value need to be
escaped with a backslash.
-Use the @code{-bsfs} option to get the list of bitstream filters.
+Use the @code{-bsfs} option to get the list of bitstream filters. E.g.
@example
-ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
+ffmpeg -bsf:v h264_mp4toannexb -i h264.mp4 -c:v copy -an out.h264
@end example
+applies the @code{h264_mp4toannexb} bitstream filter (which converts
+MP4-encapsulated H.264 stream to Annex B) to the @emph{input} video stream.
+
+On the other hand,
@example
ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
@end example
+applies the @code{mov2textsub} bitstream filter (which extracts text from MOV
+subtitles) to the @emph{output} subtitle stream. Note, however, that since both
+examples use @code{-c copy}, it matters little whether the filters are applied
+on input or output - that would change if transcoding was hapenning.
@item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{input/output,per-stream})
Force a tag/fourcc for matching streams.
diff --git a/fftools/ffmpeg_demux.c b/fftools/ffmpeg_demux.c
index eae1f0bde5..16d4f67e59 100644
--- a/fftools/ffmpeg_demux.c
+++ b/fftools/ffmpeg_demux.c
@@ -34,6 +34,7 @@
#include "libavutil/time.h"
#include "libavutil/timestamp.h"
+#include "libavcodec/bsf.h"
#include "libavcodec/packet.h"
#include "libavformat/avformat.h"
@@ -71,6 +72,8 @@ typedef struct DemuxStream {
const AVCodecDescriptor *codec_desc;
+ AVBSFContext *bsf;
+
/* number of packets successfully read for this stream */
uint64_t nb_packets;
// combined size of all the packets read
@@ -118,6 +121,8 @@ typedef struct Demuxer {
typedef struct DemuxThreadContext {
// packet used for reading from the demuxer
AVPacket *pkt_demux;
+ // packet for reading from BSFs
+ AVPacket *pkt_bsf;
} DemuxThreadContext;
static DemuxStream *ds_from_ist(InputStream *ist)
@@ -513,13 +518,17 @@ static int do_send(Demuxer *d, DemuxStream *ds, AVPacket *pkt, unsigned flags,
return 0;
}
-static int demux_send(Demuxer *d, DemuxStream *ds, AVPacket *pkt, unsigned flags)
+static int demux_send(Demuxer *d, DemuxThreadContext *dt, DemuxStream *ds,
+ AVPacket *pkt, unsigned flags)
{
InputFile *f = &d->f;
int ret;
+ // pkt can be NULL only when flushing BSFs
+ av_assert0(ds->bsf || pkt);
+
// send heartbeat for sub2video streams
- if (d->pkt_heartbeat && pkt->pts != AV_NOPTS_VALUE) {
+ if (d->pkt_heartbeat && pkt && pkt->pts != AV_NOPTS_VALUE) {
for (int i = 0; i < f->nb_streams; i++) {
DemuxStream *ds1 = ds_from_ist(f->streams[i]);
@@ -537,10 +546,69 @@ static int demux_send(Demuxer *d, DemuxStream *ds, AVPacket *pkt, unsigned flags
}
}
- ret = do_send(d, ds, pkt, flags, "demuxed");
- if (ret < 0)
- return ret;
+ if (ds->bsf) {
+ if (pkt)
+ av_packet_rescale_ts(pkt, pkt->time_base, ds->bsf->time_base_in);
+ ret = av_bsf_send_packet(ds->bsf, pkt);
+ if (ret < 0) {
+ if (pkt)
+ av_packet_unref(pkt);
+ av_log(ds, AV_LOG_ERROR, "Error submitting a packet for filtering: %s\n",
+ av_err2str(ret));
+ return ret;
+ }
+
+ while (1) {
+ ret = av_bsf_receive_packet(ds->bsf, dt->pkt_bsf);
+ if (ret == AVERROR(EAGAIN))
+ return 0;
+ else if (ret < 0) {
+ if (ret != AVERROR_EOF)
+ av_log(ds, AV_LOG_ERROR,
+ "Error applying bitstream filters to a packet: %s\n",
+ av_err2str(ret));
+ return ret;
+ }
+
+ dt->pkt_bsf->time_base = ds->bsf->time_base_out;
+
+ ret = do_send(d, ds, dt->pkt_bsf, 0, "filtered");
+ if (ret < 0) {
+ av_packet_unref(dt->pkt_bsf);
+ return ret;
+ }
+ }
+ } else {
+ ret = do_send(d, ds, pkt, flags, "demuxed");
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int demux_bsf_flush(Demuxer *d, DemuxThreadContext *dt)
+{
+ InputFile *f = &d->f;
+ int ret;
+
+ for (unsigned i = 0; i < f->nb_streams; i++) {
+ DemuxStream *ds = ds_from_ist(f->streams[i]);
+
+ if (!ds->bsf)
+ continue;
+
+ ret = demux_send(d, dt, ds, NULL, 0);
+ ret = (ret == AVERROR_EOF) ? 0 : (ret < 0) ? ret : AVERROR_BUG;
+ if (ret < 0) {
+ av_log(ds, AV_LOG_ERROR, "Error flushing BSFs: %s\n",
+ av_err2str(ret));
+ return ret;
+ }
+
+ av_bsf_flush(ds->bsf);
+ }
return 0;
}
@@ -573,6 +641,7 @@ static void thread_set_name(InputFile *f)
static void demux_thread_uninit(DemuxThreadContext *dt)
{
av_packet_free(&dt->pkt_demux);
+ av_packet_free(&dt->pkt_bsf);
memset(dt, 0, sizeof(*dt));
}
@@ -585,6 +654,10 @@ static int demux_thread_init(DemuxThreadContext *dt)
if (!dt->pkt_demux)
return AVERROR(ENOMEM);
+ dt->pkt_bsf = av_packet_alloc();
+ if (!dt->pkt_bsf)
+ return AVERROR(ENOMEM);
+
return 0;
}
@@ -619,10 +692,22 @@ static void *input_thread(void *arg)
continue;
}
if (ret < 0) {
+ int ret_bsf;
+
+ if (ret == AVERROR_EOF)
+ av_log(d, AV_LOG_VERBOSE, "EOF while reading input\n");
+ else {
+ av_log(d, AV_LOG_ERROR, "Error during demuxing: %s\n",
+ av_err2str(ret));
+ ret = exit_on_error ? ret : 0;
+ }
+
+ ret_bsf = demux_bsf_flush(d, &dt);
+ ret = err_merge(ret == AVERROR_EOF ? 0 : ret, ret_bsf);
+
if (d->loop) {
/* signal looping to our consumers */
dt.pkt_demux->stream_index = -1;
-
ret = sch_demux_send(d->sch, f->index, dt.pkt_demux, 0);
if (ret >= 0)
ret = seek_to_start(d, (Timestamp){ .ts = dt.pkt_demux->pts,
@@ -633,14 +718,6 @@ static void *input_thread(void *arg)
/* fallthrough to the error path */
}
- if (ret == AVERROR_EOF)
- av_log(d, AV_LOG_VERBOSE, "EOF while reading input\n");
- else {
- av_log(d, AV_LOG_ERROR, "Error during demuxing: %s\n",
- av_err2str(ret));
- ret = exit_on_error ? ret : 0;
- }
-
break;
}
@@ -677,7 +754,7 @@ static void *input_thread(void *arg)
if (d->readrate)
readrate_sleep(d);
- ret = demux_send(d, ds, dt.pkt_demux, send_flags);
+ ret = demux_send(d, &dt, ds, dt.pkt_demux, send_flags);
if (ret < 0)
break;
}
@@ -735,9 +812,11 @@ static void demux_final_stats(Demuxer *d)
static void ist_free(InputStream **pist)
{
InputStream *ist = *pist;
+ DemuxStream *ds;
if (!ist)
return;
+ ds = ds_from_ist(ist);
dec_free(&ist->decoder);
@@ -749,6 +828,8 @@ static void ist_free(InputStream **pist)
avcodec_free_context(&ist->dec_ctx);
avcodec_parameters_free(&ist->par);
+ av_bsf_free(&ds->bsf);
+
av_freep(pist);
}
@@ -1039,6 +1120,7 @@ static int ist_add(const OptionsContext *o, Demuxer *d, AVStream *st)
const char *hwaccel = NULL;
char *hwaccel_output_format = NULL;
char *codec_tag = NULL;
+ char *bsfs = NULL;
char *next;
char *discard_str = NULL;
int ret;
@@ -1258,6 +1340,33 @@ static int ist_add(const OptionsContext *o, Demuxer *d, AVStream *st)
return ret;
}
+ MATCH_PER_STREAM_OPT(bitstream_filters, str, bsfs, ic, st);
+ if (bsfs) {
+ ret = av_bsf_list_parse_str(bsfs, &ds->bsf);
+ if (ret < 0) {
+ av_log(ist, AV_LOG_ERROR,
+ "Error parsing bitstream filter sequence '%s': %s\n",
+ bsfs, av_err2str(ret));
+ return ret;
+ }
+
+ ret = avcodec_parameters_copy(ds->bsf->par_in, ist->par);
+ if (ret < 0)
+ return ret;
+ ds->bsf->time_base_in = ist->st->time_base;
+
+ ret = av_bsf_init(ds->bsf);
+ if (ret < 0) {
+ av_log(ist, AV_LOG_ERROR, "Error initializing bitstream filters: %s\n",
+ av_err2str(ret));
+ return ret;
+ }
+
+ ret = avcodec_parameters_copy(ist->par, ds->bsf->par_out);
+ if (ret < 0)
+ return ret;
+ }
+
ds->codec_desc = avcodec_descriptor_get(ist->par->codec_id);
return 0;
diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
index c189cf373b..76b50c0bad 100644
--- a/fftools/ffmpeg_opt.c
+++ b/fftools/ffmpeg_opt.c
@@ -1919,7 +1919,7 @@ const OptionDef options[] = {
"0 = use frame rate (video) or sample rate (audio),"
"-1 = match source time base", "ratio" },
- { "bsf", OPT_TYPE_STRING, OPT_SPEC | OPT_EXPERT | OPT_OUTPUT,
+ { "bsf", OPT_TYPE_STRING, OPT_SPEC | OPT_EXPERT | OPT_OUTPUT | OPT_INPUT,
{ .off = OFFSET(bitstream_filters) },
"A comma-separated list of bitstream filters", "bitstream_filters", },
diff --git a/tests/fate/ffmpeg.mak b/tests/fate/ffmpeg.mak
index 1bfd5c1b31..df955df4d0 100644
--- a/tests/fate/ffmpeg.mak
+++ b/tests/fate/ffmpeg.mak
@@ -256,3 +256,8 @@ FATE_SAMPLES_FFMPEG-$(call FRAMECRC, MPEGVIDEO, MPEG2VIDEO) += fate-ffmpeg-input
fate-ffmpeg-error-rate-fail: CMD = ffmpeg -i $(TARGET_SAMPLES)/mkv/h264_tta_undecodable.mkv -c:v copy -f null -; test $$? -eq 69
fate-ffmpeg-error-rate-pass: CMD = ffmpeg -i $(TARGET_SAMPLES)/mkv/h264_tta_undecodable.mkv -c:v copy -f null - -max_error_rate 1
FATE_SAMPLES_FFMPEG-$(call ENCDEC, PCM_S16LE TTA, NULL MATROSKA) += fate-ffmpeg-error-rate-fail fate-ffmpeg-error-rate-pass
+
+# test input -bsf
+# use -stream_loop, because it tests flushing bsfs
+fate-ffmpeg-bsf-input: CMD = framecrc -stream_loop 2 -bsf setts=PTS*2 -i $(TARGET_SAMPLES)/hevc/extradata-reload-multi-stsd.mov -c copy
+FATE_SAMPLES_FFMPEG-$(call FRAMECRC, MOV, , SETTS_BSF) += fate-ffmpeg-bsf-input
diff --git a/tests/ref/fate/ffmpeg-bsf-input b/tests/ref/fate/ffmpeg-bsf-input
new file mode 100644
index 0000000000..67dd57cf6d
--- /dev/null
+++ b/tests/ref/fate/ffmpeg-bsf-input
@@ -0,0 +1,18 @@
+#extradata 0: 110, 0xb4031479
+#tb 0: 1/25
+#media_type 0: video
+#codec_id 0: hevc
+#dimensions 0: 128x128
+#sar 0: 1/1
+0, 0, 0, 1, 2108, 0x57c38f64
+0, 2, 2, 1, 31, 0xabe10d25, F=0x0
+0, 4, 4, 1, 1915, 0xd430347f, S=1, 109
+0, 6, 6, 1, 35, 0xc4ad0d4c, F=0x0
+0, 8, 8, 1, 2108, 0x57c38f64, S=1, 110
+0, 10, 10, 1, 31, 0xabe10d25, F=0x0
+0, 12, 12, 1, 1915, 0xd430347f, S=1, 109
+0, 14, 14, 1, 35, 0xc4ad0d4c, F=0x0
+0, 16, 16, 1, 2108, 0x57c38f64, S=1, 110
+0, 18, 18, 1, 31, 0xabe10d25, F=0x0
+0, 20, 20, 1, 1915, 0xd430347f, S=1, 109
+0, 22, 22, 1, 35, 0xc4ad0d4c, F=0x0
--
2.42.0
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