diff options
| author | Underground78 <underground78@users.sourceforge.net> | 2012-09-22 13:06:01 +0400 |
|---|---|---|
| committer | Underground78 <underground78@users.sourceforge.net> | 2012-09-24 01:59:26 +0400 |
| commit | 915cd6a072cc9c2ccdcb17658f7ff5b0bcf42339 (patch) | |
| tree | d5ede7bda187f78f19db5f4b95278ef85c13883b /src/DSUtil/AudioParser.cpp | |
| parent | 116da51fcfe76069e0e3e0d215858e9b3d0e969a (diff) | |
MPEG Splitter/AAC Decoder: Add basic support from AAC LATM tracks.
Note that the support is probably incomplete.
This commit fixes ticket #2219 and ticket #2610.
This commit is based on ideas from MPC-BE.
Diffstat (limited to 'src/DSUtil/AudioParser.cpp')
| -rw-r--r-- | src/DSUtil/AudioParser.cpp | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/DSUtil/AudioParser.cpp b/src/DSUtil/AudioParser.cpp index 201720c7e..44499a5db 100644 --- a/src/DSUtil/AudioParser.cpp +++ b/src/DSUtil/AudioParser.cpp @@ -20,6 +20,7 @@ #include "stdafx.h"
#include "AudioParser.h"
+#include "GolombBuffer.h"
#include <MMReg.h>
#define AC3_CHANNEL 0
@@ -431,6 +432,138 @@ int ParseHdmvLPCMHeader(const BYTE* buf, int* samplerate, int* channels) return frame_size;
}
+// LATM
+
+static UINT32 LATMGetValue(CGolombBuffer& gb)
+{
+ BYTE bBytesForValue = (BYTE)gb.BitRead(2);
+ UINT32 value = 0;
+ for (int i = 0; i <= bBytesForValue; i++) {
+ value *= 256; // 2^8
+ value += gb.ReadByte();
+ }
+ return value;
+}
+
+static bool ParseLATMHeaderAudioSpecificConfig(CGolombBuffer& gb, int* samplerate, int* channels)
+{
+ static int sampling_frequency[] = { 96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000, 7350 };
+ static int channel_configuration[] = {0, 1, 2, 3, 4, 5, 6, 8};
+
+ short sAudioObjectType = (short)gb.BitRead(5);
+ if (sAudioObjectType == 31) {
+ sAudioObjectType = 32 + (short)gb.BitRead(6);
+ }
+
+ BYTE bSamplingFrequencyIndex = (BYTE)gb.BitRead(4);
+ if (bSamplingFrequencyIndex == 0xf) {
+ *samplerate = (int)gb.BitRead(24);
+ } else if (bSamplingFrequencyIndex < _countof(sampling_frequency)) {
+ *samplerate = sampling_frequency[bSamplingFrequencyIndex];
+ } else {
+ return false;
+ }
+
+ BYTE bChannelConfiguration = (BYTE)gb.BitRead(4);
+ if (bChannelConfiguration < _countof(channel_configuration)) {
+ *channels = channel_configuration[bChannelConfiguration];
+ } else {
+ return false;
+ }
+
+ int sbrPresentFlag = -1;
+ short sExtensionAudioObjectType;
+ if (sAudioObjectType == 5) {
+ sExtensionAudioObjectType = sAudioObjectType;
+ sbrPresentFlag = 1;
+
+ BYTE bExtensionSamplingFrequencyIndex = (BYTE)gb.BitRead(4);
+ if (bExtensionSamplingFrequencyIndex == 0xf) {
+ *samplerate = (int)gb.BitRead(24);
+ } else if (bExtensionSamplingFrequencyIndex < _countof(sampling_frequency)) {
+ *samplerate = sampling_frequency[bExtensionSamplingFrequencyIndex];
+ } else {
+ return false;
+ }
+
+ sAudioObjectType = (short)gb.BitRead(5);
+ if (sAudioObjectType == 31) {
+ sAudioObjectType = 32 + (short)gb.BitRead(6);
+ }
+ } else {
+ sExtensionAudioObjectType = 0;
+ }
+
+ // The specs are unclear about that but it seems to work
+ if (sbrPresentFlag == -1) {
+ *samplerate *= 2;
+ }
+
+ return true;
+}
+
+static bool ParseLATMHeaderStreamMuxConfig(CGolombBuffer& gb, int* samplerate, int* channels)
+{
+ BYTE bAudioMuxVersion = (BYTE)gb.BitRead(1);
+ BYTE bAudioMuxVersionA = 0; // default value is 0
+ if (bAudioMuxVersion) { //
+ bAudioMuxVersionA = (BYTE)gb.BitRead(1);
+ }
+
+ bool success = false;
+
+ if (bAudioMuxVersionA == 0) {
+ if (bAudioMuxVersion == 1) {
+ LATMGetValue(gb); // taraBufferFullness
+ }
+ gb.BitRead(1); // allStreamsSameTimeFraming
+ gb.BitRead(6); // numSubFrames
+ BYTE bNumProgram = (BYTE)gb.BitRead(4);
+
+ BYTE bNumLayer = (BYTE)gb.BitRead(3);
+
+ if (bNumProgram || bNumLayer) {
+ ASSERT(0); // We support only bNumProgram = bNumLayer = 0
+ return false;
+ }
+
+ BYTE bUseSameConfig = 0; // because bNumProgram = bNumLayer = 0
+ if (!bUseSameConfig) {
+ if (bAudioMuxVersion == 0) {
+ success = ParseLATMHeaderAudioSpecificConfig(gb, samplerate, channels);
+ } else{
+ UINT32 uAscLen = LATMGetValue(gb);
+ success = ParseLATMHeaderAudioSpecificConfig(gb, samplerate, channels); // TODO uAscLen -= AudioSpecificConfig();
+ // gb.BitRead((int)uAscLen); // fillBits
+ }
+ }
+ }
+
+ return success;
+}
+
+bool ParseAACLATMHeader(BYTE* buf, int len, int* samplerate, int* channels)
+{
+ *samplerate = 0;
+ *channels = 0;
+
+ CGolombBuffer gb(buf, len);
+
+ // Check LATM syncword
+ if (gb.BitRead(11) != AAC_LATM_SYNC_WORD) {
+ return false;
+ }
+ gb.BitRead(13); // audioMuxLengthBytes;
+
+ bool success = false;
+ // Parsing AudioMuxElement
+ if (!gb.BitRead(1)) { // useSameStreamMux
+ success = ParseLATMHeaderStreamMuxConfig(gb, samplerate, channels);
+ }
+
+ return success;
+}
+
// Channel masks
DWORD GetDefChannelMask(WORD nChannels)
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