This allows ending up with a normal, non-fragmented file when
the file is finished, while keeping the file readable if writing
is aborted abruptly at any point. (Normally when writing a
mov/mp4 file, the unfinished file is completely useless unless it
is finished properly.)
This results in a file where the mdat atom contains (and hides)
all the moof atoms that were part of the fragmented file structure
initially.
---
This is, incidentally, how Apple devices do (or at least did, at some
point) their writing of files when recording, at least with some
of their userspace APIs.
---
doc/muxers.texi | 7 +++++
libavformat/movenc.c | 59 ++++++++++++++++++++++++++++++++---
libavformat/movenc.h | 4 ++-
libavformat/version.h | 4 +--
tests/fate/lavf-container.mak | 3 +-
tests/ref/lavf/mov_hide_frag | 3 ++
6 files changed, 71 insertions(+), 9 deletions(-)
create mode 100644 tests/ref/lavf/mov_hide_frag
diff --git a/doc/muxers.texi b/doc/muxers.texi
index 6340c8e54d..e313b5e631 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -569,6 +569,13 @@ experimental, may be renamed or changed, do not use from
scripts.
@item write_gama
write deprecated gama atom
+
+@item hide_fragments
+After writing a fragmented file, convert it to a regular, non-fragmented
+file at the end. This keeps the file readable while it is being
+written, and makes it recoverable if the process of writing the file
+gets aborted uncleanly, while still producing an easily seekable
+and widely compatible non-fragmented file in the end.
@end table
@item movie_timescale @var{scale}
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index d1517870fc..6f044a62a7 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -110,6 +110,7 @@ static const AVOption options[] = {
{ "use_metadata_tags", "Use mdta atom for metadata.", 0,
AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_USE_MDTA}, INT_MIN, INT_MAX,
AV_OPT_FLAG_ENCODING_PARAM, .unit = "movflags" },
{ "write_colr", "Write colr atom even if the color info is unspecified
(Experimental, may be renamed or changed, do not use from scripts)", 0,
AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_WRITE_COLR}, INT_MIN, INT_MAX,
AV_OPT_FLAG_ENCODING_PARAM, .unit = "movflags" },
{ "write_gama", "Write deprecated gama atom", 0, AV_OPT_TYPE_CONST,
{.i64 = FF_MOV_FLAG_WRITE_GAMA}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM,
.unit = "movflags" },
+ { "hide_fragments", "Hide fragments at the end", 0, AV_OPT_TYPE_CONST,
{.i64 = FF_MOV_FLAG_HIDE_FRAGMENTS}, INT_MIN, INT_MAX,
AV_OPT_FLAG_ENCODING_PARAM, .unit = "movflags" },
{ "min_frag_duration", "Minimum fragment duration",
offsetof(MOVMuxContext, min_fragment_duration), AV_OPT_TYPE_INT, {.i64 = 0}, 0,
INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
{ "mov_gamma", "gamma value for gama atom", offsetof(MOVMuxContext,
gamma), AV_OPT_TYPE_FLOAT, {.dbl = 0.0 }, 0.0, 10, AV_OPT_FLAG_ENCODING_PARAM},
{ "movie_timescale", "set movie timescale", offsetof(MOVMuxContext,
movie_timescale), AV_OPT_TYPE_INT, {.i64 = MOV_TIMESCALE}, 1, INT_MAX,
AV_OPT_FLAG_ENCODING_PARAM},
@@ -5993,10 +5994,30 @@ static int mov_write_squashed_packets(AVFormatContext
*s)
return 0;
}
-static int mov_finish_fragment(MOVTrack *track)
+static int mov_finish_fragment(MOVMuxContext *mov, MOVTrack *track,
+ int64_t ref_pos)
{
+ int i;
if (!track->entry)
return 0;
+ if (mov->flags & FF_MOV_FLAG_HIDE_FRAGMENTS) {
+ for (i = 0; i < track->entry; i++)
+ track->cluster[i].pos += ref_pos + track->data_offset;
+ if (track->cluster_written == 0 && !(mov->flags &
FF_MOV_FLAG_EMPTY_MOOV)) {
+ // First flush. If this was a case of not using empty moov, reset
chunking.
+ for (i = 0; i < track->entry; i++) {
+ track->cluster[i].chunkNum = 0;
+ track->cluster[i].samples_in_chunk = track->cluster[i].entries;
+ }
+ }
+ if (av_reallocp_array(&track->cluster_written,
+ track->entry_written + track->entry,
+ sizeof(*track->cluster)))
+ return AVERROR(ENOMEM);
+ memcpy(&track->cluster_written[track->entry_written],
+ track->cluster, track->entry * sizeof(*track->cluster));
+ track->entry_written += track->entry;
+ }
track->entry = 0;
track->entries_flushed = 0;
track->end_reliable = 0;
@@ -6007,7 +6028,7 @@ static int mov_flush_fragment(AVFormatContext *s, int
force)
{
MOVMuxContext *mov = s->priv_data;
int i, first_track = -1;
- int64_t mdat_size = 0;
+ int64_t mdat_size = 0, mdat_start = 0;
int ret;
int has_video = 0, starts_with_key = 0, first_video_track = 1;
@@ -6113,7 +6134,7 @@ static int mov_flush_fragment(AVFormatContext *s, int
force)
mov->moov_written = 1;
mov->mdat_size = 0;
for (i = 0; i < mov->nb_tracks; i++)
- mov_finish_fragment(&mov->tracks[i]);
+ mov_finish_fragment(mov, &mov->tracks[i], 0);
avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_FLUSH_POINT);
return 0;
}
@@ -6182,9 +6203,10 @@ static int mov_flush_fragment(AVFormatContext *s, int
force)
avio_wb32(s->pb, mdat_size + 8);
ffio_wfourcc(s->pb, "mdat");
+ mdat_start = avio_tell(s->pb);
}
- mov_finish_fragment(&mov->tracks[i]);
+ mov_finish_fragment(mov, &mov->tracks[i], mdat_start);
if (!mov->frag_interleave) {
if (!track->mdat_buf)
continue;
@@ -7169,6 +7191,7 @@ static void mov_free(AVFormatContext *s)
else if (track->tag == MKTAG('t','m','c','d') && mov->nb_meta_tmcd)
av_freep(&track->par);
av_freep(&track->cluster);
+ av_freep(&track->cluster_written);
av_freep(&track->frag_info);
av_packet_free(&track->cover_image);
@@ -7887,6 +7910,11 @@ static int mov_write_header(AVFormatContext *s)
FF_MOV_FLAG_FRAG_EVERY_FRAME)) &&
!mov->max_fragment_duration && !mov->max_fragment_size)
mov->flags |= FF_MOV_FLAG_FRAG_KEYFRAME;
+ if (mov->flags & FF_MOV_FLAG_HIDE_FRAGMENTS) {
+ avio_wb32(pb, 8); // placeholder for extended size field (64 bit)
+ ffio_wfourcc(pb, mov->mode == MODE_MOV ? "wide" : "free");
+ mov->mdat_pos = avio_tell(pb);
+ }
} else if (mov->mode != MODE_AVIF) {
if (mov->flags & FF_MOV_FLAG_FASTSTART)
mov->reserved_header_pos = avio_tell(pb);
@@ -8090,13 +8118,34 @@ static int mov_write_trailer(AVFormatContext *s)
}
}
- if (!(mov->flags & FF_MOV_FLAG_FRAGMENT)) {
+ if (!(mov->flags & FF_MOV_FLAG_FRAGMENT) ||
+ mov->flags & FF_MOV_FLAG_HIDE_FRAGMENTS) {
+ if (mov->flags & FF_MOV_FLAG_HIDE_FRAGMENTS) {
+ mov_flush_fragment(s, 1);
+ mov->mdat_size = avio_tell(pb) - mov->mdat_pos - 8;
+ for (i = 0; i < mov->nb_tracks; i++) {
+ MOVTrack *track = &mov->tracks[i];
+ track->data_offset = 0;
+ av_free(track->cluster);
+ track->cluster = track->cluster_written;
+ track->entry = track->entry_written;
+ track->cluster_written = NULL;
+ track->entry_written = 0;
+ track->chunkCount = 0; // Force build_chunks to rebuild the
list of chunks
+ }
+ // Clear the empty_moov flag, as we do want the moov to include
+ // all the samples at this point.
+ mov->flags &= ~FF_MOV_FLAG_EMPTY_MOOV;
+ }
+
moov_pos = avio_tell(pb);
/* Write size of mdat tag */
if (mov->mdat_size + 8 <= UINT32_MAX) {
avio_seek(pb, mov->mdat_pos, SEEK_SET);
avio_wb32(pb, mov->mdat_size + 8);
+ if (mov->flags & FF_MOV_FLAG_HIDE_FRAGMENTS)
+ ffio_wfourcc(pb, "mdat"); // overwrite the original moov into
a mdat
} else {
/* overwrite 'wide' placeholder atom */
avio_seek(pb, mov->mdat_pos - 8, SEEK_SET);
diff --git a/libavformat/movenc.h b/libavformat/movenc.h
index 08d580594d..59daf8946b 100644
--- a/libavformat/movenc.h
+++ b/libavformat/movenc.h
@@ -85,7 +85,7 @@ typedef struct MOVFragmentInfo {
typedef struct MOVTrack {
int mode;
- int entry;
+ int entry, entry_written;
unsigned timescale;
uint64_t time;
int64_t track_duration;
@@ -114,6 +114,7 @@ typedef struct MOVTrack {
int vos_len;
uint8_t *vos_data;
MOVIentry *cluster;
+ MOVIentry *cluster_written;
unsigned cluster_capacity;
int audio_vbr;
int height; ///< active picture (w/o VBI) height for D-10/IMX
@@ -282,6 +283,7 @@ typedef struct MOVMuxContext {
#define FF_MOV_FLAG_SKIP_SIDX (1 << 21)
#define FF_MOV_FLAG_CMAF (1 << 22)
#define FF_MOV_FLAG_PREFER_ICC (1 << 23)
+#define FF_MOV_FLAG_HIDE_FRAGMENTS (1 << 24)
int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt);
diff --git a/libavformat/version.h b/libavformat/version.h
index 4687cd857c..af7d0a1024 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -31,8 +31,8 @@
#include "version_major.h"
-#define LIBAVFORMAT_VERSION_MINOR 3
-#define LIBAVFORMAT_VERSION_MICRO 104
+#define LIBAVFORMAT_VERSION_MINOR 4
+#define LIBAVFORMAT_VERSION_MICRO 100
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
LIBAVFORMAT_VERSION_MINOR, \
diff --git a/tests/fate/lavf-container.mak b/tests/fate/lavf-container.mak
index d84117c50f..035c394c09 100644
--- a/tests/fate/lavf-container.mak
+++ b/tests/fate/lavf-container.mak
@@ -5,7 +5,7 @@ FATE_LAVF_CONTAINER-$(call ENCDEC, FLV, FLV)
+
FATE_LAVF_CONTAINER-$(call ENCDEC, RAWVIDEO, FILMSTRIP)
+= flm
FATE_LAVF_CONTAINER-$(call ENCDEC2, MPEG2VIDEO, PCM_S16LE, GXF)
+= gxf gxf_pal gxf_ntsc
FATE_LAVF_CONTAINER-$(call ENCDEC2, MPEG4, MP2, MATROSKA)
+= mkv mkv_attachment
-FATE_LAVF_CONTAINER-$(call ENCDEC2, MPEG4, PCM_ALAW, MOV)
+= mov mov_rtphint ismv
+FATE_LAVF_CONTAINER-$(call ENCDEC2, MPEG4, PCM_ALAW, MOV)
+= mov mov_rtphint mov_hide_frag ismv
FATE_LAVF_CONTAINER-$(call ENCDEC, MPEG4, MOV)
+= mp4
FATE_LAVF_CONTAINER-$(call ENCDEC2, MPEG1VIDEO, MP2, MPEG1SYSTEM MPEGPS)
+= mpg
FATE_LAVF_CONTAINER-$(call ENCDEC , FFV1, MXF)
+= mxf_ffv1
@@ -51,6 +51,7 @@ fate-lavf-mkv: CMD = lavf_container "" "-c:a mp2 -c:v mpeg4
-ar 44100 -threads 1
fate-lavf-mkv_attachment: CMD = lavf_container_attach "-c:a mp2 -c:v mpeg4
-threads 1 -f matroska"
fate-lavf-mov: CMD = lavf_container_timecode "-movflags +faststart -c:a
pcm_alaw -c:v mpeg4 -threads 1"
fate-lavf-mov_rtphint: CMD = lavf_container "" "-movflags +rtphint -c:a
pcm_alaw -c:v mpeg4 -threads 1 -f mov"
+fate-lavf-mov_hide_frag: CMD = lavf_container "" "-movflags
+frag_keyframe+hide_fragments -c:a pcm_alaw -c:v mpeg4 -threads 1 -f mov"
fate-lavf-mp4: CMD = lavf_container_timecode "-c:v mpeg4 -an -threads 1"
fate-lavf-mpg: CMD = lavf_container_timecode "-ar 44100 -threads 1"
fate-lavf-mxf: CMD = lavf_container_timecode "-af aresample=48000:tsf=s16p -bf
2 -threads 1"
diff --git a/tests/ref/lavf/mov_hide_frag b/tests/ref/lavf/mov_hide_frag
new file mode 100644
index 0000000000..af3af5b171
--- /dev/null
+++ b/tests/ref/lavf/mov_hide_frag
@@ -0,0 +1,3 @@
+4871796f41234350f1b050317d0288a3 *tests/data/lavf/lavf.mov_hide_frag
+358508 tests/data/lavf/lavf.mov_hide_frag
+tests/data/lavf/lavf.mov_hide_frag CRC=0xbb2b949b
--
2.39.3 (Apple Git-146)
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