Re: [libav-devel] [PATCH] Add support for multichannel ATRAC3+ to OpenMG demuxer

[Maxim Polijakowski]

Hi crews,

the attached patch adds support for multichannel ATRAC3+ streams to the OpenMG demuxer. It also sets the currently wrong ATRAC3+ frame size to right one of 2048 samples.

The patch for ATRAC3+ codec itself is in preparation and will be posted shortly...

Please find attached the updated patch...

Best regards
Maxim

>From cb20dd04f8ba8342dc2992df4287b55df3b2175c Mon Sep 17 00:00:00 2001
From: Maxim Poliakovski <max_p...@gmx.de>
Date: Sat, 28 Sep 2013 00:18:18 +0200
Subject: [PATCH] Add support for multichannel ATRAC3+ streams.

---
 libavformat/oma.c    |   15 +++++++++++++++
 libavformat/oma.h    |    3 +++
 libavformat/omadec.c |   15 +++++++++++----
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/libavformat/oma.c b/libavformat/oma.c
index aaaf0b2..27b5988 100644
--- a/libavformat/oma.c
+++ b/libavformat/oma.c
@@ -21,6 +21,7 @@
 #include "internal.h"
 #include "oma.h"
 #include "libavcodec/avcodec.h"
+#include "libavutil/channel_layout.h"
 
 const uint16_t ff_oma_srate_tab[8] = { 320, 441, 480, 882, 960, 0 };
 
@@ -31,3 +32,17 @@ const AVCodecTag ff_oma_codec_tags[] = {
     { AV_CODEC_ID_PCM_S16BE,   OMA_CODECID_LPCM    },
     { 0 },
 };
+
+/** map ATRAC-X channel id to internal channel layout */
+const uint64_t ff_oma_chid_to_native_layout[7] = {
+    AV_CH_LAYOUT_MONO,
+    AV_CH_LAYOUT_STEREO,
+    AV_CH_LAYOUT_SURROUND,
+    AV_CH_LAYOUT_4POINT0,
+    AV_CH_LAYOUT_5POINT1_BACK,
+    AV_CH_LAYOUT_6POINT1_BACK,
+    AV_CH_LAYOUT_7POINT1
+};
+
+/** map ATRAC-X channel id to total number of channels */
+const int ff_oma_chid_to_num_channels[7] = {1, 2, 3, 4, 6, 7, 8};
diff --git a/libavformat/oma.h b/libavformat/oma.h
index 1f0ddf9..9a35da2 100644
--- a/libavformat/oma.h
+++ b/libavformat/oma.h
@@ -41,4 +41,7 @@ extern const uint16_t ff_oma_srate_tab[8];
 
 extern const AVCodecTag ff_oma_codec_tags[];
 
+extern const uint64_t ff_oma_chid_to_native_layout[7];
+extern const int ff_oma_chid_to_num_channels[7];
+
 #endif /* AVFORMAT_OMA_H */
diff --git a/libavformat/omadec.c b/libavformat/omadec.c
index 274112e..e5a2090 100644
--- a/libavformat/omadec.c
+++ b/libavformat/omadec.c
@@ -1,7 +1,7 @@
 /*
  * Sony OpenMG (OMA) demuxer
  *
- * Copyright (c) 2008 Maxim Poliakovski
+ * Copyright (c) 2008, 2013 Maxim Poliakovski
  *               2008 Benjamin Larsson
  *               2011 David Goldwich
  *
@@ -284,7 +284,7 @@ static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
 static int oma_read_header(AVFormatContext *s)
 {
     int     ret, framesize, jsflag, samplerate;
-    uint32_t codec_params;
+    uint32_t codec_params, channel_id;
     int16_t eid;
     uint8_t buf[EA3_HEADER_SIZE];
     uint8_t *edata;
@@ -364,7 +364,14 @@ static int oma_read_header(AVFormatContext *s)
         avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
         break;
     case OMA_CODECID_ATRAC3P:
-        st->codec->channels = (codec_params >> 10) & 7;
+        channel_id = (codec_params >> 10) & 7;
+        if (!channel_id) {
+            av_log(s, AV_LOG_ERROR,
+                   "Invalid ATRAC-X channel id: %d\n", channel_id);
+            return AVERROR_INVALIDDATA;
+        }
+        st->codec->channel_layout = ff_oma_chid_to_native_layout[channel_id - 1];
+        st->codec->channels       = ff_oma_chid_to_num_channels[channel_id - 1];
         framesize = ((codec_params & 0x3FF) * 8) + 8;
         samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
         if (!samplerate) {
@@ -372,7 +379,7 @@ static int oma_read_header(AVFormatContext *s)
             return AVERROR_INVALIDDATA;
         }
         st->codec->sample_rate = samplerate;
-        st->codec->bit_rate    = samplerate * framesize * 8 / 1024;
+        st->codec->bit_rate    = samplerate * framesize * 8 / 2048;
         avpriv_set_pts_info(st, 64, 1, samplerate);
         av_log(s, AV_LOG_ERROR, "Unsupported codec ATRAC3+!\n");
         break;
-- 
1.7.9.5


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