[FFmpeg-devel] [PATCH] avformat/aacdec: add a custom read_packet function

[James Almer]

Atempt to read and propagate only full ADTS frames and not other data,
like id3v1 or APETags at the end of the file.

Fixes ticket #6439.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavformat/aacdec.c | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/libavformat/aacdec.c b/libavformat/aacdec.c
index 5ab5197e33..f2bca996a4 100644
--- a/libavformat/aacdec.c
+++ b/libavformat/aacdec.c
@@ -23,10 +23,11 @@
 #include "libavutil/intreadwrite.h"
 #include "avformat.h"
 #include "internal.h"
-#include "rawdec.h"
 #include "id3v1.h"
 #include "apetag.h"
 
+#define ADTS_HEADER_SIZE 7
+
 static int adts_aac_probe(AVProbeData *p)
 {
     int max_frames = 0, first_frames = 0;
@@ -102,12 +103,38 @@ static int adts_aac_read_header(AVFormatContext *s)
     return 0;
 }
 
+static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    int ret, fsize;
+
+    ret = av_get_packet(s->pb, pkt, ADTS_HEADER_SIZE);
+    if (ret < 0)
+        return ret;
+    if (ret < ADTS_HEADER_SIZE) {
+        av_packet_unref(pkt);
+        return AVERROR(EIO);
+    }
+
+    if ((AV_RB16(pkt->data) >> 4) != 0xfff) {
+        av_packet_unref(pkt);
+        return AVERROR_INVALIDDATA;
+    }
+
+    fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF;
+    if (fsize < ADTS_HEADER_SIZE) {
+        av_packet_unref(pkt);
+        return AVERROR_INVALIDDATA;
+    }
+
+    return av_append_packet(s->pb, pkt, fsize - ADTS_HEADER_SIZE);
+}
+
 AVInputFormat ff_aac_demuxer = {
     .name         = "aac",
     .long_name    = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
     .read_probe   = adts_aac_probe,
     .read_header  = adts_aac_read_header,
-    .read_packet  = ff_raw_read_partial_packet,
+    .read_packet  = adts_aac_read_packet,
     .flags        = AVFMT_GENERIC_INDEX,
     .extensions   = "aac",
     .mime_type    = "audio/aac,audio/aacp,audio/x-aac",
-- 
2.12.1