[FFmpeg-cvslog] mov: support random access point grouping
Yusuke Nakamura
git at videolan.org
Thu Sep 20 22:07:38 CEST 2012
ffmpeg | branch: master | Yusuke Nakamura <muken.the.vfrmaniac at gmail.com> | Tue Apr 24 08:51:29 2012 +0900| [d17d0ec8c2b432f0b680737de0b2aa03f2d4dd8d] | committer: Luca Barbato
mov: support random access point grouping
Frames described by this grouping are the starter of a closed or
an open GOP.
This is useful for open GOP of H.264 stream which is not described
by sync sample atom.
Signed-off-by: Luca Barbato <lu_zero at gentoo.org>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d17d0ec8c2b432f0b680737de0b2aa03f2d4dd8d
---
libavformat/isom.h | 7 +++++++
libavformat/mov.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 60 insertions(+)
diff --git a/libavformat/isom.h b/libavformat/isom.h
index a766326..b191699 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -87,6 +87,11 @@ typedef struct {
unsigned flags;
} MOVTrackExt;
+typedef struct {
+ unsigned int count;
+ unsigned int index;
+} MOVSbgp;
+
typedef struct MOVStreamContext {
AVIOContext *pb;
int ffindex; ///< AVStream index
@@ -128,6 +133,8 @@ typedef struct MOVStreamContext {
int has_palette;
int64_t data_size;
int64_t track_end; ///< used for dts generation in fragmented movie files
+ unsigned int rap_group_count;
+ MOVSbgp *rap_group;
} MOVStreamContext;
typedef struct MOVContext {
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 56a075e..63049f5 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1736,6 +1736,46 @@ static int mov_read_ctts(MOVContext *c, AVIOContext *pb, MOVAtom atom)
return 0;
}
+static int mov_read_sbgp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
+{
+ AVStream *st;
+ MOVStreamContext *sc;
+ unsigned int i, entries;
+ uint8_t version;
+ uint32_t grouping_type;
+
+ if (c->fc->nb_streams < 1)
+ return 0;
+ st = c->fc->streams[c->fc->nb_streams-1];
+ sc = st->priv_data;
+
+ version = avio_r8(pb); /* version */
+ avio_rb24(pb); /* flags */
+ grouping_type = avio_rl32(pb);
+ if (grouping_type != MKTAG( 'r','a','p',' '))
+ return 0; /* only support 'rap ' grouping */
+ if (version == 1)
+ avio_rb32(pb); /* grouping_type_parameter */
+
+ entries = avio_rb32(pb);
+ if (!entries)
+ return 0;
+ if (entries >= UINT_MAX / sizeof(*sc->rap_group))
+ return AVERROR_INVALIDDATA;
+ sc->rap_group = av_malloc(entries * sizeof(*sc->rap_group));
+ if (!sc->rap_group)
+ return AVERROR(ENOMEM);
+
+ for (i = 0; i < entries && !pb->eof_reached; i++) {
+ sc->rap_group[i].count = avio_rb32(pb); /* sample_count */
+ sc->rap_group[i].index = avio_rb32(pb); /* group_description_index */
+ }
+
+ sc->rap_group_count = i;
+
+ return pb->eof_reached ? AVERROR_EOF : 0;
+}
+
static void mov_build_index(MOVContext *mov, AVStream *st)
{
MOVStreamContext *sc = st->priv_data;
@@ -1770,6 +1810,9 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
unsigned int stts_sample = 0;
unsigned int sample_size;
unsigned int distance = 0;
+ unsigned int rap_group_index = 0;
+ unsigned int rap_group_sample = 0;
+ int rap_group_present = sc->rap_group_count && sc->rap_group;
int key_off = (sc->keyframes && sc->keyframes[0] > 0) || (sc->stps_data && sc->stps_data[0] > 0);
current_dts -= sc->dts_shift;
@@ -1805,6 +1848,14 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
if (stps_index + 1 < sc->stps_count)
stps_index++;
}
+ if (rap_group_present && rap_group_index < sc->rap_group_count) {
+ if (sc->rap_group[rap_group_index].index > 0)
+ keyframe = 1;
+ if (++rap_group_sample == sc->rap_group[rap_group_index].count) {
+ rap_group_sample = 0;
+ rap_group_index++;
+ }
+ }
if (keyframe)
distance = 0;
sample_size = sc->sample_size > 0 ? sc->sample_size : sc->sample_sizes[current_sample];
@@ -2054,6 +2105,7 @@ static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom)
av_freep(&sc->keyframes);
av_freep(&sc->stts_data);
av_freep(&sc->stps_data);
+ av_freep(&sc->rap_group);
return 0;
}
@@ -2497,6 +2549,7 @@ static const MOVParseTableEntry mov_default_parse_table[] = {
{ MKTAG('c','m','o','v'), mov_read_cmov },
{ MKTAG('c','h','a','n'), mov_read_chan }, /* channel layout */
{ MKTAG('d','v','c','1'), mov_read_dvc1 },
+{ MKTAG('s','b','g','p'), mov_read_sbgp },
{ 0, NULL }
};
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