[FFmpeg-devel] [PATCH] avformat/mux: stop delaying writing the header

James Almer jamrial at gmail.com
Fri May 26 23:08:51 EEST 2017


There's no need to wait for the first packet of every stream now that
every bitstream filter behaves as intended.

Signed-off-by: James Almer <jamrial at gmail.com>
---
What should we do with the AVFMT_FLAG_AUTO_BSF flag? Do we deprecate
it and force the automatic insertion of muxer-required bitstream
filters now that the generic muxing code will always behave the same,
or keep it to give the user a choice to apply said bitstream filters?
I ask because some filters, like vp9_superframe, are necessary to
avoid creating broken files, so it's not wise to allow the user to
disable it.
It would also go in line with AVCodec.bsfs, which is essentially a
non-optional (for reasons made obvious in fa1749dd34) autobsf at the
codec level instead of container level.

The change to fate-rgb24-mkv is a regression that can be prevented by
committing https://ffmpeg.org/pipermail/ffmpeg-devel/2017-May/211311.html
or a similar solution, maybe using avformat_init_output(), to make sure
ffmpeg.c sets AVCodecParameters->field_order for the output stream before
calling avformat_write_header().

 libavformat/internal.h         |  6 -----
 libavformat/mux.c              | 53 +++++++++---------------------------------
 libavformat/options_table.h    |  2 +-
 libavformat/tests/fifo_muxer.c | 52 -----------------------------------------
 tests/ref/fate/fifo-muxer-tst  |  1 -
 tests/ref/fate/rgb24-mkv       |  4 ++--
 6 files changed, 14 insertions(+), 104 deletions(-)

diff --git a/libavformat/internal.h b/libavformat/internal.h
index c856945ce9..9c6cd77166 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -121,12 +121,6 @@ struct AVFormatInternal {
     int avoid_negative_ts_use_pts;
 
     /**
-     * Whether or not a header has already been written
-     */
-    int header_written;
-    int write_header_ret;
-
-    /**
      * Timestamp of the end of the shortest stream.
      */
     int64_t shortest_end;
diff --git a/libavformat/mux.c b/libavformat/mux.c
index 01dcb362ae..f931d6a928 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -468,26 +468,6 @@ static int init_pts(AVFormatContext *s)
     return 0;
 }
 
-static int write_header_internal(AVFormatContext *s)
-{
-    if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
-        avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_HEADER);
-    if (s->oformat->write_header) {
-        int ret = s->oformat->write_header(s);
-        if (ret >= 0 && s->pb && s->pb->error < 0)
-            ret = s->pb->error;
-        s->internal->write_header_ret = ret;
-        if (ret < 0)
-            return ret;
-        if (s->flush_packets && s->pb && s->pb->error >= 0 && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
-            avio_flush(s->pb);
-    }
-    s->internal->header_written = 1;
-    if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
-        avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_UNKNOWN);
-    return 0;
-}
-
 int avformat_init_output(AVFormatContext *s, AVDictionary **options)
 {
     int ret = 0;
@@ -526,11 +506,19 @@ int avformat_write_header(AVFormatContext *s, AVDictionary **options)
         if ((ret = avformat_init_output(s, options)) < 0)
             return ret;
 
-    if (!(s->oformat->check_bitstream && s->flags & AVFMT_FLAG_AUTO_BSF)) {
-        ret = write_header_internal(s);
+    if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
+        avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_HEADER);
+    if (s->oformat->write_header) {
+        int ret = s->oformat->write_header(s);
+        if (ret >= 0 && s->pb && s->pb->error < 0)
+            ret = s->pb->error;
         if (ret < 0)
             goto fail;
+        if (s->flush_packets && s->pb && s->pb->error >= 0 && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
+            avio_flush(s->pb);
     }
+    if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
+        avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_UNKNOWN);
 
     if (!s->internal->streams_initialized) {
         if ((ret = init_pts(s)) < 0)
@@ -756,12 +744,6 @@ FF_DISABLE_DEPRECATION_WARNINGS
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif
 
-    if (!s->internal->header_written) {
-        ret = s->internal->write_header_ret ? s->internal->write_header_ret : write_header_internal(s);
-        if (ret < 0)
-            goto fail;
-    }
-
     if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {
         AVFrame *frame = (AVFrame *)pkt->data;
         av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
@@ -778,7 +760,6 @@ FF_ENABLE_DEPRECATION_WARNINGS
             ret = s->pb->error;
     }
 
-fail:
 #if FF_API_LAVF_MERGE_SD
 FF_DISABLE_DEPRECATION_WARNINGS
     if (did_split)
@@ -926,11 +907,6 @@ int av_write_frame(AVFormatContext *s, AVPacket *pkt)
 
     if (!pkt) {
         if (s->oformat->flags & AVFMT_ALLOW_FLUSH) {
-            if (!s->internal->header_written) {
-                ret = s->internal->write_header_ret ? s->internal->write_header_ret : write_header_internal(s);
-                if (ret < 0)
-                    return ret;
-            }
             ret = s->oformat->write_packet(s, NULL);
             if (s->flush_packets && s->pb && s->pb->error >= 0 && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
                 avio_flush(s->pb);
@@ -1315,14 +1291,8 @@ int av_write_trailer(AVFormatContext *s)
             goto fail;
     }
 
-    if (!s->internal->header_written) {
-        ret = s->internal->write_header_ret ? s->internal->write_header_ret : write_header_internal(s);
-        if (ret < 0)
-            goto fail;
-    }
-
 fail:
-    if (s->internal->header_written && s->oformat->write_trailer) {
+    if (s->oformat->write_trailer) {
         if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
             avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_TRAILER);
         if (ret >= 0) {
@@ -1335,7 +1305,6 @@ fail:
     if (s->oformat->deinit)
         s->oformat->deinit(s);
 
-    s->internal->header_written =
     s->internal->initialized =
     s->internal->streams_initialized = 0;
 
diff --git a/libavformat/options_table.h b/libavformat/options_table.h
index 0c1915d6d4..250e16abe7 100644
--- a/libavformat/options_table.h
+++ b/libavformat/options_table.h
@@ -57,7 +57,7 @@ static const AVOption avformat_options[] = {
 {"seek2any", "allow seeking to non-keyframes on demuxer level when supported", OFFSET(seek2any), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, D},
 {"bitexact", "do not write random/volatile data", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_BITEXACT }, 0, 0, E, "fflags" },
 {"shortest", "stop muxing with the shortest stream", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_SHORTEST }, 0, 0, E, "fflags" },
-{"autobsf", "add needed bsfs automatically (delays header until each stream's first packet is written)", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_AUTO_BSF }, 0, 0, E, "fflags" },
+{"autobsf", "add needed bsfs automatically", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_AUTO_BSF }, 0, 0, E, "fflags" },
 {"analyzeduration", "specify how many microseconds are analyzed to probe the input", OFFSET(max_analyze_duration), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, D},
 {"cryptokey", "decryption key", OFFSET(key), AV_OPT_TYPE_BINARY, {.dbl = 0}, 0, 0, D},
 {"indexmem", "max memory used for timestamp index (per stream)", OFFSET(max_index_size), AV_OPT_TYPE_INT, {.i64 = 1<<20 }, 0, INT_MAX, D},
diff --git a/libavformat/tests/fifo_muxer.c b/libavformat/tests/fifo_muxer.c
index e20bd6e7b2..4b63df085e 100644
--- a/libavformat/tests/fifo_muxer.c
+++ b/libavformat/tests/fifo_muxer.c
@@ -238,54 +238,6 @@ fail:
     return ret;
 }
 
-static int fifo_write_header_err_tst(AVFormatContext *oc, AVDictionary **opts,
-                                     const FailingMuxerPacketData *pkt_data)
-{
-    int ret = 0, i;
-    AVPacket pkt;
-
-    av_init_packet(&pkt);
-
-    ret = avformat_write_header(oc, opts);
-    if (ret) {
-        fprintf(stderr, "Unexpected write_header failure: %s\n",
-                av_err2str(ret));
-        goto fail;
-    }
-
-    for (i = 0; i < MAX_TST_PACKETS; i++ ) {
-        ret = prepare_packet(&pkt, pkt_data, i);
-        if (ret < 0) {
-            fprintf(stderr, "Failed to prepare test packet: %s\n",
-                    av_err2str(ret));
-            goto write_trailer_and_fail;
-        }
-        ret = av_write_frame(oc, &pkt);
-        av_packet_unref(&pkt);
-        if (ret < 0) {
-            break;
-        }
-    }
-
-    if (!ret) {
-        fprintf(stderr, "write_packet not failed when supposed to.\n");
-        goto fail;
-    } else if (ret != -1) {
-        fprintf(stderr, "Unexpected write_packet error: %s\n", av_err2str(ret));
-        goto fail;
-    }
-
-    ret = av_write_trailer(oc);
-    if (ret < 0)
-        fprintf(stderr, "Unexpected write_trailer error: %s\n", av_err2str(ret));
-
-    return ret;
-write_trailer_and_fail:
-    av_write_trailer(oc);
-fail:
-    return ret;
-}
-
 static int fifo_overflow_drop_test(AVFormatContext *oc, AVDictionary **opts,
                                    const FailingMuxerPacketData *data)
 {
@@ -403,10 +355,6 @@ const TestCase tests[] = {
          * exactly what was on input */
         {fifo_basic_test, "nonfail test", NULL,1, 0, 0, {0, 0, 0}},
 
-        /* Test that we receive delayed write_header error from one of the write_packet
-         * calls. */
-        {fifo_write_header_err_tst, "write header error test", NULL, 0, -1, 0, {0, 0, 0}},
-
         /* Each write_packet will fail 3 times before operation is successful. If recovery
          * Since recovery is on, fifo muxer should not return any errors. */
         {fifo_basic_test, "recovery test", "attempt_recovery=1:recovery_wait_time=0",
diff --git a/tests/ref/fate/fifo-muxer-tst b/tests/ref/fate/fifo-muxer-tst
index ca7e294860..e1139ee0a8 100644
--- a/tests/ref/fate/fifo-muxer-tst
+++ b/tests/ref/fate/fifo-muxer-tst
@@ -2,7 +2,6 @@ flush count: 1
 pts seen nr: 15
 pts seen: 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14
 nonfail test: ok
-write header error test: ok
 recovery test: ok
 flush count: 1
 pts seen nr: 15
diff --git a/tests/ref/fate/rgb24-mkv b/tests/ref/fate/rgb24-mkv
index 4c357accaf..439b2bc5e9 100644
--- a/tests/ref/fate/rgb24-mkv
+++ b/tests/ref/fate/rgb24-mkv
@@ -1,5 +1,5 @@
-55270be3b5d393d770a1dfcb19b68271 *tests/data/fate/rgb24-mkv.matroska
-58345 tests/data/fate/rgb24-mkv.matroska
+09ee413b2d92a6be5e3b18e9e20a1f74 *tests/data/fate/rgb24-mkv.matroska
+58342 tests/data/fate/rgb24-mkv.matroska
 #tb 0: 1/10
 #media_type 0: video
 #codec_id 0: rawvideo
-- 
2.12.1



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