[FFmpeg-devel] [PATCH] avformat/mov: get the correct fragment stsd_id when decrypting the sample

[1035567130 at qq.com]

From: Wang Yaqiang <wangyaqiang03 at kuaishou.com>

When determining whether a packet should be decrypted,
should use the stsd_id of the fragment where the current packet is located.

Signed-off-by: Wang Yaqiang <wangyaqiang03 at kuaishou.com>
---
 libavformat/isom.h | 1 +
 libavformat/mov.c  | 7 ++++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/libavformat/isom.h b/libavformat/isom.h
index fd236b985f..64fb7065d5 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -139,6 +139,7 @@ typedef struct MOVFragmentStreamInfo {
     int index_base;
     int index_entry;
     MOVEncryptionIndex *encryption_index;
+    int stsd_id; // current fragment stsd_id
 } MOVFragmentStreamInfo;
 
 typedef struct MOVFragmentIndexItem {
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 35e2271b14..a2c6a4f2a3 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -4956,9 +4956,10 @@ static int mov_read_tfhd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     av_log(c->fc, AV_LOG_TRACE, "frag flags 0x%x\n", frag->flags);
 
     frag_stream_info = get_current_frag_stream_info(&c->frag_index);
-    if (frag_stream_info)
+    if (frag_stream_info) {
         frag_stream_info->next_trun_dts = AV_NOPTS_VALUE;
-
+        frag_stream_info->stsd_id = frag->stsd_id;
+    }
     return 0;
 }
 
@@ -7223,7 +7224,7 @@ static int cenc_filter(MOVContext *mov, AVStream* st, MOVStreamContext *sc, AVPa
     encryption_index = NULL;
     if (frag_stream_info) {
         // Note this only supports encryption info in the first sample descriptor.
-        if (mov->fragment.stsd_id == 1) {
+        if (frag_stream_info->stsd_id == 1) {
             if (frag_stream_info->encryption_index) {
                 encrypted_index = current_index - frag_stream_info->index_base;
                 encryption_index = frag_stream_info->encryption_index;
-- 
2.33.0