From 8bb5d1c39c9646022720ec93ef8a1b49bf558790 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <cehoyos@ag.or.at>
Date: Sat, 23 Apr 2011 10:30:18 +0200
Subject: Support channel layout when demuxing caf files.

---
 libavformat/caf.c    | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 libavformat/caf.h    |  3 +++
 libavformat/cafdec.c |  6 ++++++
 3 files changed, 67 insertions(+)

(limited to 'libavformat')

diff --git a/libavformat/caf.c b/libavformat/caf.c
index 96fb8474d2..d661406657 100644
--- a/libavformat/caf.c
+++ b/libavformat/caf.c
@@ -56,3 +56,61 @@ const AVCodecTag ff_codec_caf_tags[] = {
   /*{ MPEG4TwinVQ               MKBETAG('t','w','v','q') },*/
     { CODEC_ID_NONE,            0 },
 };
+
+typedef struct CafChannelLayout {
+    int64_t  channel_layout;
+    uint32_t layout_tag;
+} CafChannelLayout;
+
+static const CafChannelLayout caf_channel_layout[] = {
+    { AV_CH_LAYOUT_MONO,                         (100<<16) | 1}, //< kCAFChannelLayoutTag_Mono
+    { AV_CH_LAYOUT_STEREO,                       (101<<16) | 2}, //< kCAFChannelLayoutTag_Stereo
+    { AV_CH_LAYOUT_STEREO,                       (102<<16) | 2}, //< kCAFChannelLayoutTag_StereoHeadphones
+    { AV_CH_LAYOUT_2_1,                          (131<<16) | 3}, //< kCAFChannelLayoutTag_ITU_2_1
+    { AV_CH_LAYOUT_2_2,                          (132<<16) | 4}, //< kCAFChannelLayoutTag_ITU_2_2
+    { AV_CH_LAYOUT_QUAD,                         (108<<16) | 4}, //< kCAFChannelLayoutTag_Quadraphonic
+    { AV_CH_LAYOUT_SURROUND,                     (113<<16) | 3}, //< kCAFChannelLayoutTag_MPEG_3_0_A
+    { AV_CH_LAYOUT_4POINT0,                      (115<<16) | 4}, //< kCAFChannelLayoutTag_MPEG_4_0_A
+    { AV_CH_LAYOUT_5POINT0_BACK,                 (117<<16) | 5}, //< kCAFChannelLayoutTag_MPEG_5_0_A
+    { AV_CH_LAYOUT_5POINT0,                      (117<<16) | 5}, //< kCAFChannelLayoutTag_MPEG_5_0_A
+    { AV_CH_LAYOUT_5POINT1_BACK,                 (121<<16) | 6}, //< kCAFChannelLayoutTag_MPEG_5_1_A
+    { AV_CH_LAYOUT_5POINT1,                      (121<<16) | 6}, //< kCAFChannelLayoutTag_MPEG_5_1_A
+    { AV_CH_LAYOUT_7POINT1,                      (128<<16) | 8}, //< kCAFChannelLayoutTag_MPEG_7_1_C
+    { AV_CH_LAYOUT_7POINT1_WIDE,                 (126<<16) | 8}, //< kCAFChannelLayoutTag_MPEG_7_1_A
+    { AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,   (133<<16) | 3}, //< kCAFChannelLayoutTag_DVD_4
+    { AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY,      (134<<16) | 4}, //< kCAFChannelLayoutTag_DVD_5
+    { AV_CH_LAYOUT_2_2|AV_CH_LOW_FREQUENCY,      (135<<16) | 4}, //< kCAFChannelLayoutTag_DVD_6
+    { AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY, (136<<16) | 4}, //< kCAFChannelLayoutTag_DVD_10
+    { AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,  (137<<16) | 5}, //< kCAFChannelLayoutTag_DVD_11
+    { 0, 0},
+};
+
+void ff_read_chan_chunk(AVFormatContext *s, int64_t size, AVCodecContext *codec)
+{
+    uint32_t layout_tag;
+    AVIOContext *pb = s->pb;
+    const CafChannelLayout *caf_layout = caf_channel_layout;
+    if (size != 12) {
+        // Channel descriptions not implemented
+        av_log_ask_for_sample(s, "Unimplemented channel layout.");
+        avio_skip(pb, size);
+        return;
+    }
+    layout_tag = avio_rb32(pb);
+    if (layout_tag == 0x10000) { //< kCAFChannelLayoutTag_UseChannelBitmap
+        codec->channel_layout = avio_rb32(pb);
+        avio_skip(pb, 4);
+        return;
+    }
+    while (caf_layout->channel_layout) {
+        if (layout_tag == caf_layout->layout_tag) {
+            codec->channel_layout = caf_layout->channel_layout;
+            break;
+        }
+        caf_layout++;
+    }
+    if (!codec->channel_layout)
+        av_log(s, AV_LOG_WARNING, "Unknown channel layout.");
+    avio_skip(pb, 8);
+}
+
diff --git a/libavformat/caf.h b/libavformat/caf.h
index 9c25f2c683..181cfaf92a 100644
--- a/libavformat/caf.h
+++ b/libavformat/caf.h
@@ -27,8 +27,11 @@
 #ifndef AVFORMAT_CAF_H
 #define AVFORMAT_CAF_H
 
+#include "avformat.h"
 #include "internal.h"
 
 extern const AVCodecTag ff_codec_caf_tags[];
 
+void ff_read_chan_chunk(AVFormatContext *s, int64_t size, AVCodecContext *codec);
+
 #endif /* AVFORMAT_CAF_H */
diff --git a/libavformat/cafdec.c b/libavformat/cafdec.c
index 43d466f8c4..3cf4b6ca0c 100644
--- a/libavformat/cafdec.c
+++ b/libavformat/cafdec.c
@@ -257,6 +257,12 @@ static int read_header(AVFormatContext *s,
             read_info_chunk(s, size);
             break;
 
+        case MKBETAG('c','h','a','n'):
+            if (size < 12)
+                return AVERROR_INVALIDDATA;
+            ff_read_chan_chunk(s, size, st->codec);
+            break;
+
         default:
 #define _(x) ((x) >= ' ' ? (x) : ' ')
             av_log(s, AV_LOG_WARNING, "skipping CAF chunk: %08X (%c%c%c%c), size %"PRId64"\n",
-- 
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