From 1921f866ecf27b8b2b2764c24450d85577ff96c7 Mon Sep 17 00:00:00 2001
From: Matthieu Bouron <matthieu.bouron@gmail.com>
Date: Fri, 27 Sep 2019 14:57:09 +0200
Subject: avformat/mov: parse sdtp atom and set the pkt disposable flag
 accordingly

Allows the creation of the sdtp atom while remuxing MP4 to MP4. This
atom is required by Apple devices (iPhone, Apple TV) in order to accept
2160p medias.
---
 libavformat/isom.h |  2 ++
 libavformat/mov.c  | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

(limited to 'libavformat')

diff --git a/libavformat/isom.h b/libavformat/isom.h
index 69452cae8e..4943b80ccf 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -163,6 +163,8 @@ typedef struct MOVStreamContext {
     int64_t *chunk_offsets;
     unsigned int stts_count;
     MOVStts *stts_data;
+    unsigned int sdtp_count;
+    uint8_t *sdtp_data;
     unsigned int ctts_count;
     unsigned int ctts_allocated_size;
     MOVStts *ctts_data;
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 8e916a28c6..4f69664eaf 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -2959,6 +2959,40 @@ static int mov_read_stts(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     return 0;
 }
 
+static int mov_read_sdtp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
+{
+    AVStream *st;
+    MOVStreamContext *sc;
+    int64_t i, entries;
+
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams - 1];
+    sc = st->priv_data;
+
+    avio_r8(pb); /* version */
+    avio_rb24(pb); /* flags */
+    entries = atom.size - 4;
+
+    av_log(c->fc, AV_LOG_TRACE, "track[%u].sdtp.entries = %" PRId64 "\n",
+           c->fc->nb_streams - 1, entries);
+
+    if (sc->sdtp_data)
+        av_log(c->fc, AV_LOG_WARNING, "Duplicated SDTP atom\n");
+    av_freep(&sc->sdtp_data);
+    sc->sdtp_count = 0;
+
+    sc->sdtp_data = av_mallocz(entries);
+    if (!sc->sdtp_data)
+        return AVERROR(ENOMEM);
+
+    for (i = 0; i < entries && !pb->eof_reached; i++)
+        sc->sdtp_data[i] = avio_r8(pb);
+    sc->sdtp_count = i;
+
+    return 0;
+}
+
 static void mov_update_dts_shift(MOVStreamContext *sc, int duration)
 {
     if (duration < 0) {
@@ -6767,6 +6801,7 @@ static const MOVParseTableEntry mov_default_parse_table[] = {
 { MKTAG('s','t','s','z'), mov_read_stsz }, /* sample size */
 { MKTAG('s','t','t','s'), mov_read_stts },
 { MKTAG('s','t','z','2'), mov_read_stsz }, /* compact sample size */
+{ MKTAG('s','d','t','p'), mov_read_sdtp }, /* independent and disposable samples */
 { MKTAG('t','k','h','d'), mov_read_tkhd }, /* track header */
 { MKTAG('t','f','d','t'), mov_read_tfdt },
 { MKTAG('t','f','h','d'), mov_read_tfhd }, /* track fragment header */
@@ -7231,6 +7266,7 @@ static int mov_read_close(AVFormatContext *s)
         av_freep(&sc->sample_sizes);
         av_freep(&sc->keyframes);
         av_freep(&sc->stts_data);
+        av_freep(&sc->sdtp_data);
         av_freep(&sc->stps_data);
         av_freep(&sc->elst_data);
         av_freep(&sc->rap_group);
@@ -7820,6 +7856,11 @@ static int mov_read_packet(AVFormatContext *s, AVPacket *pkt)
     }
     if (st->discard == AVDISCARD_ALL)
         goto retry;
+    if (sc->sdtp_data && sc->current_sample <= sc->sdtp_count) {
+        uint8_t sample_flags = sc->sdtp_data[sc->current_sample - 1];
+        uint8_t sample_is_depended_on = (sample_flags >> 2) & 0x3;
+        pkt->flags |= sample_is_depended_on == MOV_SAMPLE_DEPENDENCY_NO ? AV_PKT_FLAG_DISPOSABLE : 0;
+    }
     pkt->flags |= sample->flags & AVINDEX_KEYFRAME ? AV_PKT_FLAG_KEY : 0;
     pkt->pos = sample->pos;
 
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