[FFmpeg-devel] [PATCH 4/4] Move audio channel API from libavcodec to libavcore.

Stefano Sabatini stefano.sabatini-lala
Sat Oct 30 06:49:41 CEST 2010


---
 libavcodec/audioconvert.c |   91 +++------------------------------
 libavcodec/audioconvert.h |   21 ++++---
 libavcodec/avcodec.h      |   80 +++++++++++++++-------------
 libavcore/Makefile        |    6 ++-
 libavcore/audioconvert.c  |  125 +++++++++++++++++++++++++++++++++++++++++++++
 libavcore/audioconvert.h  |  108 ++++++++++++++++++++++++++++++++++++++
 6 files changed, 299 insertions(+), 132 deletions(-)
 create mode 100644 libavcore/audioconvert.c
 create mode 100644 libavcore/audioconvert.h

diff --git a/libavcodec/audioconvert.c b/libavcodec/audioconvert.c
index 4e4063f..f3d483c 100644
--- a/libavcodec/audioconvert.c
+++ b/libavcodec/audioconvert.c
@@ -48,104 +48,27 @@ void avcodec_sample_fmt_string (char *buf, int buf_size, int sample_fmt)
 }
 #endif
 
-static const char* const channel_names[]={
-    "FL", "FR", "FC", "LFE", "BL",  "BR",  "FLC", "FRC",
-    "BC", "SL", "SR", "TC",  "TFL", "TFC", "TFR", "TBL",
-    "TBC", "TBR",
-    [29] = "DL",
-    [30] = "DR",
-};
-
-static const char *get_channel_name(int channel_id)
-{
-    if (channel_id<0 || channel_id>=FF_ARRAY_ELEMS(channel_names))
-        return NULL;
-    return channel_names[channel_id];
-}
-
+#if FF_API_OLD_AUDIOCONVERT
 int64_t avcodec_guess_channel_layout(int nb_channels, enum CodecID codec_id, const char *fmt_name)
 {
-    switch(nb_channels) {
-    case 1: return CH_LAYOUT_MONO;
-    case 2: return CH_LAYOUT_STEREO;
-    case 3: return CH_LAYOUT_SURROUND;
-    case 4: return CH_LAYOUT_QUAD;
-    case 5: return CH_LAYOUT_5POINT0;
-    case 6: return CH_LAYOUT_5POINT1;
-    case 8: return CH_LAYOUT_7POINT1;
-    default: return 0;
-    }
+    return av_guess_channel_layout(nb_channels);
 }
 
-static const struct {
-    const char *name;
-    int         nb_channels;
-    int64_t     layout;
-} channel_layout_map[] = {
-    { "mono",        1,  CH_LAYOUT_MONO },
-    { "stereo",      2,  CH_LAYOUT_STEREO },
-    { "4.0",         4,  CH_LAYOUT_4POINT0 },
-    { "quad",        4,  CH_LAYOUT_QUAD },
-    { "5.0",         5,  CH_LAYOUT_5POINT0 },
-    { "5.0",         5,  CH_LAYOUT_5POINT0_BACK },
-    { "5.1",         6,  CH_LAYOUT_5POINT1 },
-    { "5.1",         6,  CH_LAYOUT_5POINT1_BACK },
-    { "5.1+downmix", 8,  CH_LAYOUT_5POINT1|CH_LAYOUT_STEREO_DOWNMIX, },
-    { "7.1",         8,  CH_LAYOUT_7POINT1 },
-    { "7.1(wide)",   8,  CH_LAYOUT_7POINT1_WIDE },
-    { "7.1+downmix", 10, CH_LAYOUT_7POINT1|CH_LAYOUT_STEREO_DOWNMIX, },
-    { 0 }
-};
-
 int64_t avcodec_get_channel_layout(const char *name)
 {
-    int i = 0;
-    do {
-        if (!strcmp(channel_layout_map[i].name, name))
-            return channel_layout_map[i].layout;
-        i++;
-    } while (channel_layout_map[i].name);
-
-    return 0;
+    return av_get_channel_layout(name);
 }
 
-void avcodec_get_channel_layout_string(char *buf, int buf_size, int nb_channels, int64_t channel_layout)
+void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, int64_t channel_layout)
 {
-    int i;
-
-    for (i=0; channel_layout_map[i].name; i++)
-        if (nb_channels    == channel_layout_map[i].nb_channels &&
-            channel_layout == channel_layout_map[i].layout) {
-            av_strlcpy(buf, channel_layout_map[i].name, buf_size);
-            return;
-        }
-
-    snprintf(buf, buf_size, "%d channels", nb_channels);
-    if (channel_layout) {
-        int i,ch;
-        av_strlcat(buf, " (", buf_size);
-        for(i=0,ch=0; i<64; i++) {
-            if ((channel_layout & (1L<<i))) {
-                const char *name = get_channel_name(i);
-                if (name) {
-                    if (ch>0) av_strlcat(buf, "|", buf_size);
-                    av_strlcat(buf, name, buf_size);
-                }
-                ch++;
-            }
-        }
-        av_strlcat(buf, ")", buf_size);
-    }
+    return av_get_channel_layout_string(buf, buf_size, nb_channels, channel_layout);
 }
 
 int avcodec_channel_layout_num_channels(int64_t channel_layout)
 {
-    int count;
-    uint64_t x = channel_layout;
-    for (count = 0; x; count++)
-        x &= x-1; // unset lowest set bit
-    return count;
+    return av_get_channel_layout_nb_channels(channel_layout);
 }
+#endif
 
 struct AVAudioConvert {
     int in_channels, out_channels;
diff --git a/libavcodec/audioconvert.h b/libavcodec/audioconvert.h
index e7d262b..302281e 100644
--- a/libavcodec/audioconvert.h
+++ b/libavcodec/audioconvert.h
@@ -52,34 +52,37 @@ attribute_deprecated
 enum SampleFormat avcodec_get_sample_fmt(const char* name);
 #endif
 
+#if FF_API_OLD_AUDIOCONVERT
 /**
- * @return NULL on error
+ * @deprecated Use av_get_channel_name() instead.
  */
+attribute_deprecated
 const char *avcodec_get_channel_name(int channel_id);
 
 /**
- * @return channel layout that matches name, 0 if no match
+ * @deprecated Use av_get_channel_layout() instead.
  */
+attribute_deprecated
 int64_t avcodec_get_channel_layout(const char *name);
 
 /**
- * Return description of channel layout
+ * @deprecated Use av_get_channel_layout_string() instead.
  */
+attribute_deprecated
 void avcodec_get_channel_layout_string(char *buf, int buf_size, int nb_channels, int64_t channel_layout);
 
 /**
- * Guess the channel layout
- * @param nb_channels
- * @param codec_id Codec identifier, or CODEC_ID_NONE if unknown
- * @param fmt_name Format name, or NULL if unknown
- * @return Channel layout mask
+ * @deprecated Use av_guess_channel_layout() instead.
  */
+attribute_deprecated
 int64_t avcodec_guess_channel_layout(int nb_channels, enum CodecID codec_id, const char *fmt_name);
 
 /**
- * @return the number of channels in the channel layout.
+ * @deprecated Use av_get_channel_layout_nb_channels() instead.
  */
+attribute_deprecated
 int avcodec_channel_layout_num_channels(int64_t channel_layout);
+#endif
 
 struct AVAudioConvert;
 typedef struct AVAudioConvert AVAudioConvert;
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 62d2441..e3960ab 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -79,6 +79,9 @@
 #ifndef FF_API_OLD_SAMPLE_FMT
 #define FF_API_OLD_SAMPLE_FMT   (LIBAVCODEC_VERSION_MAJOR < 53)
 #endif
+#ifndef FF_API_OLD_AUDIOCONVERT
+#define FF_API_OLD_AUDIOCONVERT (LIBAVCODEC_VERSION_MAJOR < 54)
+#endif
 
 #define AV_NOPTS_VALUE          INT64_C(0x8000000000000000)
 #define AV_TIME_BASE            1000000
@@ -425,50 +428,53 @@ enum CodecID {
 #define SAMPLE_FMT_NB   AV_SAMPLE_FMT_NB
 #endif
 
+#if FF_API_OLD_AUDIOCONVERT
+#include "libavcore/audioconvert.h"
+
 /* Audio channel masks */
-#define CH_FRONT_LEFT             0x00000001
-#define CH_FRONT_RIGHT            0x00000002
-#define CH_FRONT_CENTER           0x00000004
-#define CH_LOW_FREQUENCY          0x00000008
-#define CH_BACK_LEFT              0x00000010
-#define CH_BACK_RIGHT             0x00000020
-#define CH_FRONT_LEFT_OF_CENTER   0x00000040
-#define CH_FRONT_RIGHT_OF_CENTER  0x00000080
-#define CH_BACK_CENTER            0x00000100
-#define CH_SIDE_LEFT              0x00000200
-#define CH_SIDE_RIGHT             0x00000400
-#define CH_TOP_CENTER             0x00000800
-#define CH_TOP_FRONT_LEFT         0x00001000
-#define CH_TOP_FRONT_CENTER       0x00002000
-#define CH_TOP_FRONT_RIGHT        0x00004000
-#define CH_TOP_BACK_LEFT          0x00008000
-#define CH_TOP_BACK_CENTER        0x00010000
-#define CH_TOP_BACK_RIGHT         0x00020000
-#define CH_STEREO_LEFT            0x20000000  ///< Stereo downmix.
-#define CH_STEREO_RIGHT           0x40000000  ///< See CH_STEREO_LEFT.
+#define CH_FRONT_LEFT            AV_CH_FRONT_LEFT
+#define CH_FRONT_RIGHT           AV_CH_FRONT_RIGHT
+#define CH_FRONT_CENTER          AV_CH_FRONT_CENTER
+#define CH_LOW_FREQUENCY         AV_CH_LOW_FREQUENCY
+#define CH_BACK_LEFT             AV_CH_BACK_LEFT
+#define CH_BACK_RIGHT            AV_CH_BACK_RIGHT
+#define CH_FRONT_LEFT_OF_CENTER  AV_CH_FRONT_LEFT_OF_CENTER
+#define CH_FRONT_RIGHT_OF_CENTER AV_CH_FRONT_RIGHT_OF_CENTER
+#define CH_BACK_CENTER           AV_CH_BACK_CENTER
+#define CH_SIDE_LEFT             AV_CH_SIDE_LEFT
+#define CH_SIDE_RIGHT            AV_CH_SIDE_RIGHT
+#define CH_TOP_CENTER            AV_CH_TOP_CENTER
+#define CH_TOP_FRONT_LEFT        AV_CH_TOP_FRONT_LEFT
+#define CH_TOP_FRONT_CENTER      AV_CH_TOP_FRONT_CENTER
+#define CH_TOP_FRONT_RIGHT       AV_CH_TOP_FRONT_RIGHT
+#define CH_TOP_BACK_LEFT         AV_CH_TOP_BACK_LEFT
+#define CH_TOP_BACK_CENTER       AV_CH_TOP_BACK_CENTER
+#define CH_TOP_BACK_RIGHT        AV_CH_TOP_BACK_RIGHT
+#define CH_STEREO_LEFT           AV_CH_STEREO_LEFT
+#define CH_STEREO_RIGHT          AV_CH_STEREO_RIGHT
 
 /** Channel mask value used for AVCodecContext.request_channel_layout
     to indicate that the user requests the channel order of the decoder output
     to be the native codec channel order. */
-#define CH_LAYOUT_NATIVE          0x8000000000000000LL
+#define CH_LAYOUT_NATIVE         AV_CH_LAYOUT_NATIVE
 
 /* Audio channel convenience macros */
-#define CH_LAYOUT_MONO              (CH_FRONT_CENTER)
-#define CH_LAYOUT_STEREO            (CH_FRONT_LEFT|CH_FRONT_RIGHT)
-#define CH_LAYOUT_2_1               (CH_LAYOUT_STEREO|CH_BACK_CENTER)
-#define CH_LAYOUT_SURROUND          (CH_LAYOUT_STEREO|CH_FRONT_CENTER)
-#define CH_LAYOUT_4POINT0           (CH_LAYOUT_SURROUND|CH_BACK_CENTER)
-#define CH_LAYOUT_2_2               (CH_LAYOUT_STEREO|CH_SIDE_LEFT|CH_SIDE_RIGHT)
-#define CH_LAYOUT_QUAD              (CH_LAYOUT_STEREO|CH_BACK_LEFT|CH_BACK_RIGHT)
-#define CH_LAYOUT_5POINT0           (CH_LAYOUT_SURROUND|CH_SIDE_LEFT|CH_SIDE_RIGHT)
-#define CH_LAYOUT_5POINT1           (CH_LAYOUT_5POINT0|CH_LOW_FREQUENCY)
-#define CH_LAYOUT_5POINT0_BACK      (CH_LAYOUT_SURROUND|CH_BACK_LEFT|CH_BACK_RIGHT)
-#define CH_LAYOUT_5POINT1_BACK      (CH_LAYOUT_5POINT0_BACK|CH_LOW_FREQUENCY)
-#define CH_LAYOUT_7POINT0           (CH_LAYOUT_5POINT0|CH_BACK_LEFT|CH_BACK_RIGHT)
-#define CH_LAYOUT_7POINT1           (CH_LAYOUT_5POINT1|CH_BACK_LEFT|CH_BACK_RIGHT)
-#define CH_LAYOUT_7POINT1_WIDE      (CH_LAYOUT_5POINT1_BACK|\
-                                          CH_FRONT_LEFT_OF_CENTER|CH_FRONT_RIGHT_OF_CENTER)
-#define CH_LAYOUT_STEREO_DOWNMIX    (CH_STEREO_LEFT|CH_STEREO_RIGHT)
+#define CH_LAYOUT_MONO           AV_CH_LAYOUT_MONO
+#define CH_LAYOUT_STEREO         AV_CH_LAYOUT_STEREO
+#define CH_LAYOUT_2_1            AV_CH_LAYOUT_2_1
+#define CH_LAYOUT_SURROUND       AV_CH_LAYOUT_SURROUND
+#define CH_LAYOUT_4POINT0        AV_CH_LAYOUT_4POINT0
+#define CH_LAYOUT_2_2            AV_CH_LAYOUT_2_2
+#define CH_LAYOUT_QUAD           AV_CH_LAYOUT_QUAD
+#define CH_LAYOUT_5POINT0        AV_CH_LAYOUT_5POINT0
+#define CH_LAYOUT_5POINT1        AV_CH_LAYOUT_5POINT1
+#define CH_LAYOUT_5POINT0_BACK   AV_CH_LAYOUT_5POINT0_BACK
+#define CH_LAYOUT_5POINT1_BACK   AV_CH_LAYOUT_5POINT1_BACK
+#define CH_LAYOUT_7POINT0        AV_CH_LAYOUT_7POINT0
+#define CH_LAYOUT_7POINT1        AV_CH_LAYOUT_7POINT1
+#define CH_LAYOUT_7POINT1_WIDE   AV_CH_LAYOUT_7POINT1_WIDE
+#define CH_LAYOUT_STEREO_DOWNMIX AV_CH_LAYOUT_STEREO_DOWNMIX
+#endif
 
 /* in bytes */
 #define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio
diff --git a/libavcore/Makefile b/libavcore/Makefile
index 037f55e..2426ba1 100644
--- a/libavcore/Makefile
+++ b/libavcore/Makefile
@@ -3,12 +3,14 @@ include $(SUBDIR)../config.mak
 NAME = avcore
 FFLIBS = avutil
 
-HEADERS = avcore.h                                                      \
+HEADERS = audioconvert.h                                                \
+          avcore.h                                                      \
           imgutils.h                                                    \
           parseutils.h                                                  \
           samplefmt.h                                                   \
 
-OBJS = imgutils.o                                                       \
+OBJS = audioconvert.o                                                   \
+       imgutils.o                                                       \
        parseutils.o                                                     \
        samplefmt.o                                                      \
        utils.o                                                          \
diff --git a/libavcore/audioconvert.c b/libavcore/audioconvert.c
new file mode 100644
index 0000000..2b6e1a8
--- /dev/null
+++ b/libavcore/audioconvert.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2006 Michael Niedermayer <michaelni at gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * audio conversion routines
+ */
+
+#include "audioconvert.h"
+
+static const char * const channel_names[] = {
+    "FL", "FR", "FC", "LFE", "BL",  "BR",  "FLC", "FRC",
+    "BC", "SL", "SR", "TC",  "TFL", "TFC", "TFR", "TBL",
+    "TBC", "TBR",
+    [29] = "DL",
+    [30] = "DR",
+};
+
+static const char *get_channel_name(int channel_id)
+{
+    if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
+        return NULL;
+    return channel_names[channel_id];
+}
+
+int64_t av_guess_channel_layout(int nb_channels)
+{
+    switch (nb_channels) {
+    case 1: return AV_CH_LAYOUT_MONO;
+    case 2: return AV_CH_LAYOUT_STEREO;
+    case 3: return AV_CH_LAYOUT_SURROUND;
+    case 4: return AV_CH_LAYOUT_QUAD;
+    case 5: return AV_CH_LAYOUT_5POINT0;
+    case 6: return AV_CH_LAYOUT_5POINT1;
+    case 8: return AV_CH_LAYOUT_7POINT1;
+    default: return 0;
+    }
+}
+
+static const struct {
+    const char *name;
+    int         nb_channels;
+    int64_t     layout;
+} channel_layout_map[] = {
+    { "mono",        1,  AV_CH_LAYOUT_MONO },
+    { "stereo",      2,  AV_CH_LAYOUT_STEREO },
+    { "4.0",         4,  AV_CH_LAYOUT_4POINT0 },
+    { "quad",        4,  AV_CH_LAYOUT_QUAD },
+    { "5.0",         5,  AV_CH_LAYOUT_5POINT0 },
+    { "5.0",         5,  AV_CH_LAYOUT_5POINT0_BACK },
+    { "5.1",         6,  AV_CH_LAYOUT_5POINT1 },
+    { "5.1",         6,  AV_CH_LAYOUT_5POINT1_BACK },
+    { "5.1+downmix", 8,  AV_CH_LAYOUT_5POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
+    { "7.1",         8,  AV_CH_LAYOUT_7POINT1 },
+    { "7.1(wide)",   8,  AV_CH_LAYOUT_7POINT1_WIDE },
+    { "7.1+downmix", 10, AV_CH_LAYOUT_7POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
+    { 0 }
+};
+
+int64_t av_get_channel_layout(const char *name)
+{
+    int i = 0;
+    do {
+        if (!strcmp(channel_layout_map[i].name, name))
+            return channel_layout_map[i].layout;
+        i++;
+    } while (channel_layout_map[i].name);
+
+    return 0;
+}
+
+void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, int64_t channel_layout)
+{
+    int i;
+
+    for (i = 0; channel_layout_map[i].name; i++)
+        if (nb_channels    == channel_layout_map[i].nb_channels &&
+            channel_layout == channel_layout_map[i].layout) {
+            av_strlcpy(buf, channel_layout_map[i].name, buf_size);
+            return;
+        }
+
+    snprintf(buf, buf_size, "%d channels", nb_channels);
+    if (channel_layout) {
+        int i,ch;
+        av_strlcat(buf, " (", buf_size);
+        for(i=0,ch=0; i<64; i++) {
+            if ((channel_layout & (1L<<i))) {
+                const char *name = get_channel_name(i);
+                if (name) {
+                    if (ch>0) av_strlcat(buf, "|", buf_size);
+                    av_strlcat(buf, name, buf_size);
+                }
+                ch++;
+            }
+        }
+        av_strlcat(buf, ")", buf_size);
+    }
+}
+
+int av_get_channel_layout_nb_channels(int64_t channel_layout)
+{
+    int count;
+    uint64_t x = channel_layout;
+    for (count = 0; x; count++)
+        x &= x-1; // unset lowest set bit
+    return count;
+}
diff --git a/libavcore/audioconvert.h b/libavcore/audioconvert.h
new file mode 100644
index 0000000..08341dc
--- /dev/null
+++ b/libavcore/audioconvert.h
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2006 Michael Niedermayer <michaelni at gmx.at>
+ * Copyright (c) 2008 Peter Ross
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCORE_AUDIOCONVERT_H
+#define AVCORE_AUDIOCONVERT_H
+
+/**
+ * @file
+ * audio conversion routines
+ */
+
+#include "avcore.h"
+
+/* Audio channel masks */
+#define AV_CH_FRONT_LEFT             0x00000001
+#define AV_CH_FRONT_RIGHT            0x00000002
+#define AV_CH_FRONT_CENTER           0x00000004
+#define AV_CH_LOW_FREQUENCY          0x00000008
+#define AV_CH_BACK_LEFT              0x00000010
+#define AV_CH_BACK_RIGHT             0x00000020
+#define AV_CH_FRONT_LEFT_OF_CENTER   0x00000040
+#define AV_CH_FRONT_RIGHT_OF_CENTER  0x00000080
+#define AV_CH_BACK_CENTER            0x00000100
+#define AV_CH_SIDE_LEFT              0x00000200
+#define AV_CH_SIDE_RIGHT             0x00000400
+#define AV_CH_TOP_CENTER             0x00000800
+#define AV_CH_TOP_FRONT_LEFT         0x00001000
+#define AV_CH_TOP_FRONT_CENTER       0x00002000
+#define AV_CH_TOP_FRONT_RIGHT        0x00004000
+#define AV_CH_TOP_BACK_LEFT          0x00008000
+#define AV_CH_TOP_BACK_CENTER        0x00010000
+#define AV_CH_TOP_BACK_RIGHT         0x00020000
+#define AV_CH_STEREO_LEFT            0x20000000  ///< Stereo downmix.
+#define AV_CH_STEREO_RIGHT           0x40000000  ///< See AV_CH_STEREO_LEFT.
+
+/** Channel mask value used for AVCodecContext.request_channel_layout
+    to indicate that the user requests the channel order of the decoder output
+    to be the native codec channel order. */
+#define AV_CH_LAYOUT_NATIVE          0x8000000000000000LL
+
+/* Audio channel convenience macros */
+#define AV_CH_LAYOUT_MONO              (AV_CH_FRONT_CENTER)
+#define AV_CH_LAYOUT_STEREO            (AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT)
+#define AV_CH_LAYOUT_2_1               (AV_CH_LAYOUT_STEREO|AV_CH_BACK_CENTER)
+#define AV_CH_LAYOUT_SURROUND          (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER)
+#define AV_CH_LAYOUT_4POINT0           (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_CENTER)
+#define AV_CH_LAYOUT_2_2               (AV_CH_LAYOUT_STEREO|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
+#define AV_CH_LAYOUT_QUAD              (AV_CH_LAYOUT_STEREO|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
+#define AV_CH_LAYOUT_5POINT0           (AV_CH_LAYOUT_SURROUND|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
+#define AV_CH_LAYOUT_5POINT1           (AV_CH_LAYOUT_5POINT0|AV_CH_LOW_FREQUENCY)
+#define AV_CH_LAYOUT_5POINT0_BACK      (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
+#define AV_CH_LAYOUT_5POINT1_BACK      (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_LOW_FREQUENCY)
+#define AV_CH_LAYOUT_7POINT0           (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
+#define AV_CH_LAYOUT_7POINT1           (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
+#define AV_CH_LAYOUT_7POINT1_WIDE      (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
+#define AV_CH_LAYOUT_STEREO_DOWNMIX    (AV_CH_STEREO_LEFT|AV_CH_STEREO_RIGHT)
+
+/**
+ * Return a string describing an audio channel with channel_id, or
+ * NULL if the channel_id is unknown.
+ */
+const char *av_get_channel_name(int channel_id);
+
+/**
+ * Return a channel layout id that matches name, 0 if no match.
+ */
+int64_t av_get_channel_layout(const char *name);
+
+/**
+ * Return description of channel layout.
+ *
+ * @param buf put here the string containing the channel layout
+ * @param buf_size size in bytes of the buffer
+ */
+void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, int64_t channel_layout);
+
+/**
+ * Guess the channel layout.
+ *
+ * @param nb_channels
+ * @return channel layout mask
+ */
+int64_t av_guess_channel_layout(int nb_channels);
+
+/**
+ * Return the number of channels in the channel layout.
+ */
+int av_get_channel_layout_nb_channels(int64_t channel_layout);
+
+#endif /* AVCORE_AUDIOCONVERT_H */
-- 
1.7.1




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