[FFmpeg-devel] [PATCH] avformat/avidec: add support for recognizing HEVC fourcc when demuxing

[Marton Balint]

Some security cams generate this, as well as some versions of VirtualDub so
support for _reading_ such files is justified.

Fixes ticket #7110.

See also this discussion: https://patchwork.ffmpeg.org/patch/8744/

Signed-off-by: Marton Balint <cus at passwd.hu>
---
 libavformat/avidec.c | 4 ++++
 libavformat/riff.c   | 5 +++++
 libavformat/riff.h   | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/libavformat/avidec.c b/libavformat/avidec.c
index 1d887b1cc9..7946791fe4 100644
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -815,6 +815,10 @@ FF_ENABLE_DEPRECATION_WARNINGS
                                   "mov tag found in avi (fourcc %s)\n",
                                   av_fourcc2str(tag1));
                     }
+                    /* Finally try unofficial codec tags to support non-standard files. */
+                    if (!st->codecpar->codec_id)
+                        st->codecpar->codec_id = ff_codec_get_id(ff_codec_bmp_tags_unofficial, tag1);
+
                     /* This is needed to get the pict type which is necessary
                      * for generating correct pts. */
                     st->need_parsing = AVSTREAM_PARSE_HEADERS;
diff --git a/libavformat/riff.c b/libavformat/riff.c
index e755ad8d5f..52b0bf8f03 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -491,6 +491,11 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { AV_CODEC_ID_NONE,         0 }
 };
 
+const AVCodecTag ff_codec_bmp_tags_unofficial[] = {
+    { AV_CODEC_ID_HEVC,         MKTAG('H', 'E', 'V', 'C') },
+    { AV_CODEC_ID_NONE,         0 }
+};
+
 const AVCodecTag ff_codec_wav_tags[] = {
     { AV_CODEC_ID_PCM_S16LE,       0x0001 },
     /* must come after s16le in this list */
diff --git a/libavformat/riff.h b/libavformat/riff.h
index 323aa38b4d..21078b77c8 100644
--- a/libavformat/riff.h
+++ b/libavformat/riff.h
@@ -73,6 +73,8 @@ int ff_get_wav_header(AVFormatContext *s, AVIOContext *pb, AVCodecParameters *pa
 extern const AVCodecTag ff_codec_bmp_tags[]; // exposed through avformat_get_riff_video_tags()
 extern const AVCodecTag ff_codec_wav_tags[];
 
+extern const AVCodecTag ff_codec_bmp_tags_unofficial[];
+
 void ff_parse_specific_params(AVStream *st, int *au_rate, int *au_ssize, int *au_scale);
 
 int ff_read_riff_info(AVFormatContext *s, int64_t size);
-- 
2.16.4