[FFmpeg-cvslog] avformat/iamf_parse: fix parsing AAC DecoderConfigDescriptor

[James Almer]

ffmpeg | branch: release/7.0 | James Almer <jamrial at gmail.com> | Thu Aug 29 21:39:02 2024 -0300| [098ab0cd9987392bd54383cb8a8f1cee848a7000] | committer: James Almer

avformat/iamf_parse: fix parsing AAC DecoderConfigDescriptor

Use ff_mp4_read_descr() to read both the tags and the vlc value
that comes after it, which was not being taken into account.

Ref: https://github.com/AOMediaCodec/libiamf/issues/119

Signed-off-by: James Almer <jamrial at gmail.com>
(cherry picked from commit 38bcb3ba7b3424abd772c72f8bdf445d75285e88)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=098ab0cd9987392bd54383cb8a8f1cee848a7000
---

 libavformat/iamf_parse.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/libavformat/iamf_parse.c b/libavformat/iamf_parse.c
index 3abbf70c8d..d6b7be81c0 100644
--- a/libavformat/iamf_parse.c
+++ b/libavformat/iamf_parse.c
@@ -67,7 +67,7 @@ static int aac_decoder_config(IAMFCodecConfig *codec_config,
     if (codec_config->audio_roll_distance >= 0)
         return AVERROR_INVALIDDATA;
 
-    tag = avio_r8(pb);
+    ff_mp4_read_descr(logctx, pb, &tag);
     if (tag != MP4DecConfigDescrTag)
         return AVERROR_INVALIDDATA;
 
@@ -87,12 +87,9 @@ static int aac_decoder_config(IAMFCodecConfig *codec_config,
     if (codec_id && codec_id != codec_config->codec_id)
         return AVERROR_INVALIDDATA;
 
-    tag = avio_r8(pb);
-    if (tag != MP4DecSpecificDescrTag)
-        return AVERROR_INVALIDDATA;
-
-    left = len - avio_tell(pb);
-    if (left <= 0)
+    left = ff_mp4_read_descr(logctx, pb, &tag);
+    if (tag != MP4DecSpecificDescrTag ||
+        !left || left > (len - avio_tell(pb)))
         return AVERROR_INVALIDDATA;
 
     // We pad extradata here because avpriv_mpeg4audio_get_config2() needs it.
@@ -100,9 +97,9 @@ static int aac_decoder_config(IAMFCodecConfig *codec_config,
     if (!codec_config->extradata)
         return AVERROR(ENOMEM);
 
-    codec_config->extradata_size = avio_read(pb, codec_config->extradata, left);
-    if (codec_config->extradata_size < left)
-        return AVERROR_INVALIDDATA;
+    codec_config->extradata_size = ffio_read_size(pb, codec_config->extradata, left);
+    if (ret < 0)
+        return ret;
     memset(codec_config->extradata + codec_config->extradata_size, 0,
            AV_INPUT_BUFFER_PADDING_SIZE);