[FFmpeg-cvslog] avformat/riff: prevent muxing adpcm_swf with a variable block size

[Zane van Iperen]

ffmpeg | branch: master | Zane van Iperen <zane at zanevaniperen.com> | Fri Oct 16 00:02:18 2020 +1000| [53ac499f0132b924315ce26c2683d6eb1717ce29] | committer: Zane van Iperen

avformat/riff: prevent muxing adpcm_swf with a variable block size

Prefer to error than to create a broken file. Closes ticket #5829.

Effectively disables remuxing adpcm_swf from flv -> wav.

Signed-off-by: Zane van Iperen <zane at zanevaniperen.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=53ac499f0132b924315ce26c2683d6eb1717ce29
---

 libavformat/riffenc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavformat/riffenc.c b/libavformat/riffenc.c
index 04a21fcffa..df04b31893 100644
--- a/libavformat/riffenc.c
+++ b/libavformat/riffenc.c
@@ -65,6 +65,12 @@ int ff_put_wav_header(AVFormatContext *s, AVIOContext *pb,
     if (!par->codec_tag || par->codec_tag > 0xffff)
         return -1;
 
+    if (par->codec_id == AV_CODEC_ID_ADPCM_SWF && par->block_align == 0) {
+        av_log(s, AV_LOG_ERROR, "%s can only be written to WAVE with a constant frame size\n",
+               avcodec_get_name(par->codec_id));
+        return AVERROR(EINVAL);
+    }
+
     /* We use the known constant frame size for the codec if known, otherwise
      * fall back on using AVCodecContext.frame_size, which is not as reliable
      * for indicating packet duration. */