[FFmpeg-devel] [PATCH] avformat/mpeg: fix detection and demuxing of raw AC3 in mpegps

Paul B Mahol onemda at gmail.com
Fri Mar 30 19:46:06 EEST 2018


Fixes #4889.

Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavformat/mpeg.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c
index 69d4a9d8ac..f6e3439e68 100644
--- a/libavformat/mpeg.c
+++ b/libavformat/mpeg.c
@@ -128,6 +128,7 @@ typedef struct MpegDemuxContext {
     int sofdec;
     int dvd;
     int imkh_cctv;
+    int raw_ac3;
 #if CONFIG_VOBSUB_DEMUXER
     AVFormatContext *sub_ctx;
     FFDemuxSubtitlesQueue q[32];
@@ -443,7 +444,15 @@ redo:
 
     if (startcode == PRIVATE_STREAM_1) {
         startcode = avio_r8(s->pb);
-        len--;
+        if (avio_r8(s->pb) == 0x77 && startcode == 0x0b) {
+            startcode = 0x80;
+            m->raw_ac3 = 1;
+            avio_skip(s->pb, -2);
+        } else {
+            m->raw_ac3 = 0;
+            avio_skip(s->pb, -1);
+            len--;
+        }
     }
     if (len < 0)
         goto error_redo;
@@ -486,14 +495,16 @@ redo:
         if (len < 4)
             goto skip;
 
-        /* audio: skip header */
-        avio_r8(s->pb);
-        lpcm_header_len = avio_rb16(s->pb);
-        len -= 3;
-        if (startcode >= 0xb0 && startcode <= 0xbf) {
-            /* MLP/TrueHD audio has a 4-byte header */
+        if (!m->raw_ac3) {
+            /* audio: skip header */
             avio_r8(s->pb);
-            len--;
+            lpcm_header_len = avio_rb16(s->pb);
+            len -= 3;
+            if (startcode >= 0xb0 && startcode <= 0xbf) {
+                /* MLP/TrueHD audio has a 4-byte header */
+                avio_r8(s->pb);
+                len--;
+            }
         }
     }
 
-- 
2.11.0



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