[FFmpeg-devel] [PATCH] lavf/movenc: Fail when codec tag is invalid for format

[John Stebbins]

Fixes ticket #6897
---
 libavformat/movenc.c | 40 +++++++++++++++++++++++++++++-----------
 1 file changed, 29 insertions(+), 11 deletions(-)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 72a6e12d52..93bb50ce86 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1589,6 +1589,26 @@ static const AVCodecTag codec_cover_image_tags[] = {
     { AV_CODEC_ID_NONE, 0 },
 };
 
+static int validate_codec_tag(const AVCodecTag *const *tags,
+                              unsigned int tag, int codec_id)
+{
+    int i;
+
+    /**
+     * Check that tag + id is in the table
+     */
+    for (i = 0; tags && tags[i]; i++) {
+        const AVCodecTag *codec_tags = tags[i];
+        while (codec_tags->id != AV_CODEC_ID_NONE) {
+            if (codec_tags->tag == tag && codec_tags->id == codec_id) {
+                return 1;
+            }
+            codec_tags++;
+        }
+    }
+    return 0;
+}
+
 static int mov_find_codec_tag(AVFormatContext *s, MOVTrack *track)
 {
     int tag;
@@ -1596,23 +1616,21 @@ static int mov_find_codec_tag(AVFormatContext *s, MOVTrack *track)
     if (is_cover_image(track->st))
         return ff_codec_get_tag(codec_cover_image_tags, track->par->codec_id);
 
-    if (track->mode == MODE_MP4 || track->mode == MODE_PSP)
-        tag = track->par->codec_tag;
-    else if (track->mode == MODE_ISM)
-        tag = track->par->codec_tag;
-    else if (track->mode == MODE_IPOD) {
+    if (track->mode == MODE_IPOD)
         if (!av_match_ext(s->url, "m4a") &&
             !av_match_ext(s->url, "m4v") &&
             !av_match_ext(s->url, "m4b"))
             av_log(s, AV_LOG_WARNING, "Warning, extension is not .m4a nor .m4v "
                    "Quicktime/Ipod might not play the file\n");
-        tag = track->par->codec_tag;
-    } else if (track->mode & MODE_3GP)
-        tag = track->par->codec_tag;
-    else if (track->mode == MODE_F4V)
-        tag = track->par->codec_tag;
-    else
+
+    if (track->mode == MODE_MOV)
         tag = mov_get_codec_tag(s, track);
+    else
+        if (!validate_codec_tag(s->oformat->codec_tag, track->par->codec_tag,
+                                track->par->codec_id))
+            tag = 0;
+        else
+            tag = track->par->codec_tag;
 
     return tag;
 }
-- 
2.17.1