[FFmpeg-devel] [PATCH 1/3] lavf: identify MP2 as a distinct container from MP3

[Rodger Combs]

This allows us to report the correct codec ID here
---
 libavformat/allformats.c |  2 +-
 libavformat/mp3dec.c     | 62 +++++++++++++++++++++++++++++++-----------------
 libavformat/version.h    |  2 +-
 3 files changed, 42 insertions(+), 24 deletions(-)

diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 6a79b75d78..6fd8aa609b 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -189,7 +189,7 @@ void av_register_all(void)
     REGISTER_DEMUXER (MM,               mm);
     REGISTER_MUXDEMUX(MMF,              mmf);
     REGISTER_MUXDEMUX(MOV,              mov);
-    REGISTER_MUXER   (MP2,              mp2);
+    REGISTER_MUXDEMUX(MP2,              mp2);
     REGISTER_MUXDEMUX(MP3,              mp3);
     REGISTER_MUXER   (MP4,              mp4);
     REGISTER_DEMUXER (MPC,              mpc);
diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
index 099ca57d24..499aa45fd4 100644
--- a/libavformat/mp3dec.c
+++ b/libavformat/mp3dec.c
@@ -66,7 +66,7 @@ static int check(AVIOContext *pb, int64_t pos, uint32_t *header);
 
 /* mp3 read */
 
-static int mp3_read_probe(AVProbeData *p)
+static int mpa_read_probe(AVProbeData *p, int layer)
 {
     int max_frames, first_frames = 0;
     int whole_used = 0;
@@ -89,7 +89,7 @@ static int mp3_read_probe(AVProbeData *p)
 
             header = AV_RB32(buf2);
             ret = avpriv_mpegaudio_decode_header(&h, header);
-            if (ret != 0)
+            if (ret != 0 || h.layer != layer)
                 break;
             buf2 += h.frame_size;
         }
@@ -113,6 +113,12 @@ static int mp3_read_probe(AVProbeData *p)
 //mpegps_mp3_unrecognized_format.mpg has max_frames=3
 }
 
+#define READ_PROBE(l) \
+static int mp##l##_read_probe(AVProbeData *p) \
+{ \
+    return mpa_read_probe(p, l); \
+}
+
 static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration)
 {
     int i;
@@ -341,7 +347,7 @@ static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
     return 0;
 }
 
-static int mp3_read_header(AVFormatContext *s)
+static int mpa_read_header(AVFormatContext *s, enum AVCodecID id)
 {
     MP3DecContext *mp3 = s->priv_data;
     AVStream *st;
@@ -354,7 +360,7 @@ static int mp3_read_header(AVFormatContext *s)
         return AVERROR(ENOMEM);
 
     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
-    st->codecpar->codec_id = AV_CODEC_ID_MP3;
+    st->codecpar->codec_id = id;
     st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
     st->start_time = 0;
 
@@ -419,6 +425,12 @@ static int mp3_read_header(AVFormatContext *s)
     return 0;
 }
 
+#define READ_HEADER(l) \
+static int mp##l##_read_header(AVFormatContext *s) \
+{ \
+    return mpa_read_header(s, AV_CODEC_ID_MP##l); \
+}
+
 #define MP3_PACKET_SIZE 1024
 
 static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
@@ -579,23 +591,29 @@ static const AVOption options[] = {
     { NULL },
 };
 
-static const AVClass demuxer_class = {
-    .class_name = "mp3",
-    .item_name  = av_default_item_name,
-    .option     = options,
-    .version    = LIBAVUTIL_VERSION_INT,
-    .category   = AV_CLASS_CATEGORY_DEMUXER,
+#define DECLARE_LAYER(l, ext) \
+READ_PROBE(l) \
+READ_HEADER(l) \
+static const AVClass demuxer_class_##l = { \
+    .class_name = "mp" #l, \
+    .item_name  = av_default_item_name, \
+    .option     = options, \
+    .version    = LIBAVUTIL_VERSION_INT, \
+    .category   = AV_CLASS_CATEGORY_DEMUXER, \
+}; \
+\
+AVInputFormat ff_mp##l##_demuxer = { \
+    .name           = "mp" #l, \
+    .long_name      = NULL_IF_CONFIG_SMALL("MP" #l " (MPEG audio layer " #l ")"), \
+    .read_probe     = mp##l##_read_probe, \
+    .read_header    = mp##l##_read_header, \
+    .read_packet    = mp3_read_packet, \
+    .read_seek      = mp3_seek, \
+    .priv_data_size = sizeof(MP3DecContext), \
+    .flags          = AVFMT_GENERIC_INDEX, \
+    .extensions     = ext, /* XXX: use probe */ \
+    .priv_class     = &demuxer_class_##l, \
 };
 
-AVInputFormat ff_mp3_demuxer = {
-    .name           = "mp3",
-    .long_name      = NULL_IF_CONFIG_SMALL("MP2/3 (MPEG audio layer 2/3)"),
-    .read_probe     = mp3_read_probe,
-    .read_header    = mp3_read_header,
-    .read_packet    = mp3_read_packet,
-    .read_seek      = mp3_seek,
-    .priv_data_size = sizeof(MP3DecContext),
-    .flags          = AVFMT_GENERIC_INDEX,
-    .extensions     = "mp2,mp3,m2a,mpa", /* XXX: use probe */
-    .priv_class     = &demuxer_class,
-};
+DECLARE_LAYER(2, "mp2,m2a,mpa")
+DECLARE_LAYER(3, "mp3,mpa")
diff --git a/libavformat/version.h b/libavformat/version.h
index 65e6a4ccb7..21cc8a99c7 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -32,7 +32,7 @@
 // Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium)
 // Also please add any ticket numbers that you believe might be affected here
 #define LIBAVFORMAT_VERSION_MAJOR  57
-#define LIBAVFORMAT_VERSION_MINOR  61
+#define LIBAVFORMAT_VERSION_MINOR  62
 #define LIBAVFORMAT_VERSION_MICRO 100
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
-- 
2.11.0