stdin

commit 918f5590d43c6f7a39d2986bf446fde73093319d
Author: Rodger Combs <rodger.combs@gmail.com>
Date:   Thu May 7 20:16:39 2015 -0500

    lavf/aacenc: Add support for 7.1-channel output
    
    In future, we should probably allow writing a PCE for non-standard
    channel layouts, and we might want to do that for 7.1 as well (since
    there's history of that layout being used incorrectly; this patch
    actually does that).

diff --git a/libavcodec/aacenc.c b/libavcodec/aacenc.c
index 998a875..8222b18 100644
--- a/libavcodec/aacenc.c
+++ b/libavcodec/aacenc.c
@@ -45,8 +45,6 @@
 
 #include "psymodel.h"
 
-#define AAC_MAX_CHANNELS 6
-
 #define ERROR_IF(cond, ...) \
     if (cond) { \
         av_log(avctx, AV_LOG_ERROR, __VA_ARGS__); \
@@ -142,13 +140,15 @@ static const uint8_t *swb_size_128[] = {
 };
 
 /** default channel configurations */
-static const uint8_t aac_chan_configs[6][5] = {
+static const uint8_t aac_chan_configs[8][6] = {
  {1, TYPE_SCE},                               // 1 channel  - single channel element
  {1, TYPE_CPE},                               // 2 channels - channel pair
  {2, TYPE_SCE, TYPE_CPE},                     // 3 channels - center + stereo
  {3, TYPE_SCE, TYPE_CPE, TYPE_SCE},           // 4 channels - front center + stereo + back center
  {3, TYPE_SCE, TYPE_CPE, TYPE_CPE},           // 5 channels - front center + stereo + back stereo
  {4, TYPE_SCE, TYPE_CPE, TYPE_CPE, TYPE_LFE}, // 6 channels - front center + stereo + back stereo + LFE
+ {4, TYPE_SCE, TYPE_CPE, TYPE_CPE, TYPE_CPE}, // 7 channels - front center + stereo + surround stereo + back stereo
+ {5, TYPE_SCE, TYPE_CPE, TYPE_CPE, TYPE_CPE, TYPE_LFE}, // 8 channels - front center + stereo + surround stereo + back stereo + LFE
 };
 
 /**
@@ -161,6 +161,8 @@ static const uint8_t aac_chan_maps[AAC_MAX_CHANNELS][AAC_MAX_CHANNELS] = {
     { 2, 0, 1, 3 },
     { 2, 0, 1, 3, 4 },
     { 2, 0, 1, 4, 5, 3 },
+    { 2, 0, 1, 5, 6, 3, 4 },
+    { 2, 0, 1, 6, 7, 4, 5, 3 },
 };
 
 /**
@@ -175,7 +177,7 @@ static void put_audio_specific_config(AVCodecContext *avctx)
     init_put_bits(&pb, avctx->extradata, avctx->extradata_size);
     put_bits(&pb, 5, 2); //object type - AAC-LC
     put_bits(&pb, 4, s->samplerate_index); //sample rate index
-    put_bits(&pb, 4, s->channels);
+    put_bits(&pb, 4, s->channel_configuration);
     //GASpecificConfig
     put_bits(&pb, 1, 0); //frame length - 1024 samples
     put_bits(&pb, 1, 0); //does not depend on core coder
@@ -756,6 +758,15 @@ alloc_fail:
     return AVERROR(ENOMEM);
 }
 
+static av_cold int get_channel_configuration(int channels)
+{
+    if (channels < 7)
+        return channels;
+    else if (channels == 8)
+        return 7;
+    return 0;
+}
+
 static av_cold int aac_encode_init(AVCodecContext *avctx)
 {
     AACEncContext *s = avctx->priv_data;
@@ -771,12 +782,13 @@ static av_cold int aac_encode_init(AVCodecContext *avctx)
             break;
 
     s->channels = avctx->channels;
+    s->channel_configuration = get_channel_configuration(s->channels);
 
     ERROR_IF(i == 16
                 || i >= (sizeof(swb_size_1024) / sizeof(*swb_size_1024))
                 || i >= (sizeof(swb_size_128) / sizeof(*swb_size_128)),
              "Unsupported sample rate %d\n", avctx->sample_rate);
-    ERROR_IF(s->channels > AAC_MAX_CHANNELS,
+    ERROR_IF(s->channel_configuration == 0,
              "Unsupported number of channels: %d\n", s->channels);
     ERROR_IF(avctx->profile != FF_PROFILE_UNKNOWN && avctx->profile != FF_PROFILE_AAC_LOW,
              "Unsupported profile %d\n", avctx->profile);
diff --git a/libavcodec/aacenc.h b/libavcodec/aacenc.h
index 7c1f277..125b75a 100644
--- a/libavcodec/aacenc.h
+++ b/libavcodec/aacenc.h
@@ -30,6 +30,8 @@
 #include "audio_frame_queue.h"
 #include "psymodel.h"
 
+#define AAC_MAX_CHANNELS 8
+
 typedef enum AACCoder {
     AAC_CODER_FAAC = 0,
     AAC_CODER_ANMR,
@@ -69,10 +71,11 @@ typedef struct AACEncContext {
     FFTContext mdct1024;                         ///< long (1024 samples) frame transform context
     FFTContext mdct128;                          ///< short (128 samples) frame transform context
     AVFloatDSPContext *fdsp;
-    float *planar_samples[6];                    ///< saved preprocessed input
+    float *planar_samples[AAC_MAX_CHANNELS];     ///< saved preprocessed input
 
     int samplerate_index;                        ///< MPEG-4 samplerate index
     int channels;                                ///< channel count
+    int channel_configuration;                   ///< channel configuration ID
     const uint8_t *chan_map;                     ///< channel configuration map
 
     ChannelElement *cpe;                         ///< channel elements