* ac3_decoder.cpp
* Copyright (C) 2004 Marcus Overhagen <marcus@overhagen.de>
*
* This file is part of an AC-3 decoder plugin for the OpenBeOS
* media kit. OpenBeOS can be found at http://www.openbeos.org
*
* This file is distributed under the terms of the MIT license.
* You can also use it under the terms of the GPL version 2.
*
* Since this file is linked against a GPL licensed library,
* the combined work of this file and the liba52 library, the
* ac3_decoder plugin must be distributed as GPL licensed.
*/
#include <malloc.h>
#include <string.h>
#include <stdio.h>
#include <ReaderPlugin.h>
#include "ac3_decoder.h"
#if 0
#define TRACE printf
#else
#define TRACE(a...)
#endif
AC3Decoder::AC3Decoder()
: fInputBuffer(0)
, fInputBufferSize(0)
, fInputChunk(0)
, fInputChunkSize(0)
, fInputChunkOffset(0)
, fStartTime(0)
, fHasStreamInfo(false)
, fDisableDynamicCompression(false)
, fChannelCount(0)
, fChannelMask(0)
{
fInputBuffer = malloc(INPUT_BUFFER_MAX_SIZE);
strcpy(fChannelInfo,"Unknown");
fState = a52_init(0);
if (fState) {
fSamples = a52_samples(fState);
}
}
AC3Decoder::~AC3Decoder()
{
free(fInputBuffer);
if (fState) {
a52_free(fState);
}
}
void
AC3Decoder::GetCodecInfo(media_codec_info *info)
{
if (info) {
strcpy(info->short_name, "AC-3");
sprintf(info->pretty_name,"%s AC-3 decoded by liba52",fChannelInfo);
}
}
status_t
AC3Decoder::Setup(media_format *ioEncodedFormat,
const void *infoBuffer, size_t infoSize)
{
if (!fState) {
return B_ERROR;
}
if (!fHasStreamInfo)
fHasStreamInfo = GetStreamInfo();
if (!fHasStreamInfo) {
TRACE("AC3Decoder::Setup: couldn't get stream info\n");
return B_ERROR;
}
if (fFlags & A52_LFE) {
fChannelCount = 1;
fChannelMask = B_CHANNEL_SUB;
} else {
fChannelCount = 0;
fChannelMask = 0;
}
fInterleaveOffset = 0;
switch (fFlags & A52_CHANNEL_MASK) {
case A52_CHANNEL:
{
if (fFlags & A52_LFE) {
strcpy(fChannelInfo,"2.1 Channel");
} else {
strcpy(fChannelInfo,"2 Channel");
}
fChannelCount += 2;
fChannelMask |= B_CHANNEL_LEFT | B_CHANNEL_RIGHT;
static int lfe_offsets[6] = { 2, 0, 1 };
static int nrm_offsets[6] = { 0, 1 };
fInterleaveOffset = (fFlags & A52_LFE) ? lfe_offsets : nrm_offsets;
break;
}
case A52_MONO: {
if (fFlags & A52_LFE) {
strcpy(fChannelInfo,"Mono + Sub");
} else {
strcpy(fChannelInfo,"Mono");
}
fChannelCount += 1;
fChannelMask |= B_CHANNEL_LEFT;
static int lfe_offsets[6] = { 1, 0 };
static int nrm_offsets[6] = { 0 };
fInterleaveOffset = (fFlags & A52_LFE) ? lfe_offsets : nrm_offsets;
break;
}
case A52_STEREO:
{
if (fFlags & A52_LFE) {
strcpy(fChannelInfo,"Stereo + Sub");
} else {
strcpy(fChannelInfo,"Stereo");
}
fChannelCount += 2;
fChannelMask |= B_CHANNEL_LEFT | B_CHANNEL_RIGHT;
static int lfe_offsets[6] = { 2, 0, 1 };
static int nrm_offsets[6] = { 0, 1 };
fInterleaveOffset = (fFlags & A52_LFE) ? lfe_offsets : nrm_offsets;
break;
}
case A52_3F:
{
if (fFlags & A52_LFE) {
strcpy(fChannelInfo,"3.1 front Channel");
} else {
strcpy(fChannelInfo,"3 front Channel");
}
fChannelCount += 3;
fChannelMask |= B_CHANNEL_LEFT | B_CHANNEL_RIGHT | B_CHANNEL_CENTER;
static int lfe_offsets[6] = { 3, 0, 2, 1 };
static int nrm_offsets[6] = { 0, 2, 1 };
fInterleaveOffset = (fFlags & A52_LFE) ? lfe_offsets : nrm_offsets;
break;
}
case A52_2F1R:
{
if (fFlags & A52_LFE) {
strcpy(fChannelInfo,"2.1 front 1 rear Channel");
} else {
strcpy(fChannelInfo,"2 front 1 rear Channel");
}
fChannelCount += 3;
fChannelMask |= B_CHANNEL_LEFT | B_CHANNEL_RIGHT | B_CHANNEL_BACK_CENTER;
static int lfe_offsets[6] = { 2, 0, 3, 1 };
static int nrm_offsets[6] = { 0, 2, 1 };
fInterleaveOffset = (fFlags & A52_LFE) ? lfe_offsets : nrm_offsets;
break;
}
case A52_3F1R:
{
if (fFlags & A52_LFE) {
strcpy(fChannelInfo,"3.1 front 1 rear Channel");
} else {
strcpy(fChannelInfo,"3 front 1 rear Channel");
}
fChannelCount += 4;
fChannelMask |= B_CHANNEL_LEFT | B_CHANNEL_RIGHT | B_CHANNEL_CENTER | B_CHANNEL_BACK_CENTER;
static int lfe_offsets[6] = { 3, 0, 2, 1, 4 };
static int nrm_offsets[6] = { 0, 2, 1, 3 };
fInterleaveOffset = (fFlags & A52_LFE) ? lfe_offsets : nrm_offsets;
break;
}
case A52_2F2R:
{
if (fFlags & A52_LFE) {
strcpy(fChannelInfo,"2.1 front 2 rear Channel");
} else {
strcpy(fChannelInfo,"2 front 2 rear Channel");
}
fChannelCount += 4;
fChannelMask |= B_CHANNEL_LEFT | B_CHANNEL_RIGHT | B_CHANNEL_REARLEFT | B_CHANNEL_REARRIGHT;
static int lfe_offsets[6] = { 2, 0, 1, 3, 4};
static int nrm_offsets[6] = { 0, 1, 2, 3 };
fInterleaveOffset = (fFlags & A52_LFE) ? lfe_offsets : nrm_offsets;
break;
}
case A52_3F2R:
{
if (fFlags & A52_LFE) {
strcpy(fChannelInfo,"3.1 front 2 rear Channel");
} else {
strcpy(fChannelInfo,"3 front 2 rear Channel");
}
fChannelCount += 5;
fChannelMask |= B_CHANNEL_LEFT | B_CHANNEL_RIGHT | B_CHANNEL_CENTER | B_CHANNEL_REARLEFT | B_CHANNEL_REARRIGHT;
static int lfe_offsets[6] = { 3, 0, 2, 1, 4, 5 };
static int nrm_offsets[6] = { 0, 2, 1, 3, 4 };
fInterleaveOffset = (fFlags & A52_LFE) ? lfe_offsets : nrm_offsets;
break;
}
case A52_DOLBY:
{
if (fFlags & A52_LFE) {
strcpy(fChannelInfo,"Dolby stereo + Sub");
} else {
strcpy(fChannelInfo,"Dolby stereo");
}
fChannelCount += 2;
fChannelMask |= B_CHANNEL_LEFT | B_CHANNEL_RIGHT;
static int lfe_offsets[6] = { 2, 0, 1 };
static int nrm_offsets[6] = { 0, 1 };
fInterleaveOffset = (fFlags & A52_LFE) ? lfe_offsets : nrm_offsets;
break;
}
default:
TRACE("AC3Decoder::NegotiateOutputFormat: can't decode channel setup\n");
return B_ERROR;
}
fFlags = A52_STEREO & A52_CHANNEL_MASK;
fChannelCount = 2;
fChannelMask = B_CHANNEL_LEFT | B_CHANNEL_RIGHT;
static int nrm_offsets[6] = { 0, 1 };
fInterleaveOffset = nrm_offsets;
return B_OK;
}
status_t
AC3Decoder::NegotiateOutputFormat(media_format *ioDecodedFormat)
{
ioDecodedFormat->type = B_MEDIA_RAW_AUDIO;
ioDecodedFormat->u.raw_audio.frame_rate = fFrameRate;
ioDecodedFormat->u.raw_audio.channel_count = fChannelCount;
ioDecodedFormat->u.raw_audio.format = media_raw_audio_format::B_AUDIO_FLOAT;
ioDecodedFormat->u.raw_audio.byte_order = B_MEDIA_HOST_ENDIAN;
fFrameSize = (ioDecodedFormat->u.raw_audio.format & 0xf) * ioDecodedFormat->u.raw_audio.channel_count;
ioDecodedFormat->u.raw_audio.buffer_size = 6 * 256 * fFrameSize;
ioDecodedFormat->u.raw_audio.channel_mask = fChannelMask;
TRACE("AC3Decoder::NegotiateOutputFormat: fFlags 0x%x, fFrameRate %d, fBitRate %d, fChannelCount %d, fFrameSize %d\n", fFlags, fFrameRate, fBitRate, fChannelCount, fFrameSize);
return B_OK;
}
status_t
AC3Decoder::Seek(uint32 seekTo,
int64 seekFrame, int64 *frame,
bigtime_t seekTime, bigtime_t *time)
{
fInputChunkSize = 0;
fInputBufferSize = 0;
TRACE("AC3Decoder::Seek called\n");
if (seekTo == B_MEDIA_SEEK_TO_TIME) {
TRACE("AC3Decoder::Seek by time ");
TRACE("from frame %Ld and time %Ld TO Required Time %Ld. ", *frame, *time, seekTime);
*frame = (int64)(*time / (fFrameSize * 1000000.0 / fFrameRate));
} else if (seekTo == B_MEDIA_SEEK_TO_FRAME) {
TRACE("AC3Decoder::Seek by Frame ");
TRACE("from Current Time %Ld and frame %Ld TO Required Frame %Ld. ", *time, *frame, seekFrame);
*time = (bigtime_t)(*frame * fFrameSize * 1000000.0 / fFrameRate);
} else
return B_BAD_VALUE;
TRACE("so new frame is %Ld at time %Ld\n", *frame, *time);
return B_OK;
}
status_t
AC3Decoder::Decode(void *buffer, int64 *frameCount,
media_header *mediaHeader, media_decode_info *info)
{
if (!DecodeNext()) {
TRACE("AC3Decoder::Decode: DecodeNext failed\n");
return B_ERROR;
}
Every A/52 frame is composed of 6 blocks, each with an output of 256
samples for each channel. The a52_block() function decodes the next
block in the frame, and should be called 6 times to decode all of the
audio in the frame. After each call, you should extract the audio data
from the sample buffer.
*/
for (int i = 0; i < 6; i++) {
a52_block(fState);
for (int j = 0; j < fChannelCount; j++) {
float *buf = (float *) buffer;
buf += i * 256 * fChannelCount + fInterleaveOffset[j];
for (int k = 0; k < 256; k++) {
*buf = fSamples[j * 256 + k];
buf += fChannelCount;
}
}
}
mediaHeader->start_time = fStartTime;
mediaHeader->type = B_MEDIA_RAW_AUDIO;
mediaHeader->size_used = 6 * 256 * fFrameSize;
mediaHeader->data_offset = 0;
fStartTime += 6 * 256 * 1000000LL / fFrameRate;
*frameCount = 6 * 256;
return B_OK;
}
bool
AC3Decoder::InputGetData(void **buffer, int size)
{
TRACE("AC3Decoder::InputGetData: %d bytes enter\n", size);
for (;;) {
if (fInputBufferSize >= size) {
*buffer = fInputBuffer;
TRACE("AC3Decoder::InputGetData: finished\n");
return true;
}
if (fInputChunkSize > 0) {
int bytes = min_c(size - fInputBufferSize, fInputChunkSize);
memcpy((char *)fInputBuffer + fInputBufferSize, (char *)fInputChunk + fInputChunkOffset, bytes);
fInputChunkOffset += bytes;
fInputChunkSize -= bytes;
fInputBufferSize += bytes;
continue;
}
while (fInputChunkSize == 0) {
fInputChunkOffset = 0;
media_header mh;
if (B_OK != GetNextChunk(&fInputChunk, &fInputChunkSize, &mh)) {
TRACE("AC3Decoder::InputGetData: failed\n");
return false;
}
fStartTime = mh.start_time;
TRACE("AC3Decoder::InputGetData: got new chunk, %ld bytes, start time %Ld\n", fInputChunkSize, fStartTime);
}
}
}
void
AC3Decoder::InputRemoveData(int size)
{
fInputBufferSize -= size;
if (fInputBufferSize)
memmove(fInputBuffer, (char *)fInputBuffer + size, fInputBufferSize);
}
bool
AC3Decoder::GetStreamInfo()
{
for (;;) {
void *input;
if (!InputGetData(&input, 7)) {
TRACE("AC3Decoder::GetStreamInfo: can't get 7 bytes\n");
return false;
}
if (0 != a52_syncinfo((uint8_t *)input, &fFlags, &fFrameRate, &fBitRate))
return true;
TRACE("AC3Decoder::GetStreamInfo: a52_syncinfo failed\n");
InputRemoveData(1);
}
}
bool
AC3Decoder::DecodeNext()
{
for (;;) {
void *input;
if (!InputGetData(&input, 7)) {
TRACE("AC3Decoder::DecodeNext: can't get 7 bytes\n");
return false;
}
int flags, sample_rate, bit_rate;
int bytes = a52_syncinfo((uint8_t *)input, &flags, &sample_rate, &bit_rate);
if (bytes == 0) {
TRACE("AC3Decoder::DecodeNext: syncinfo failed\n");
InputRemoveData(1);
continue;
}
TRACE("AC3Decoder::DecodeNext: %d, %d\n",sample_rate, bit_rate);
if (!InputGetData(&input, bytes)) {
TRACE("AC3Decoder::DecodeNext: can't get %d data bytes\n", bytes);
return false;
}
flags = fFlags | A52_ADJUST_LEVEL;
sample_t level = 1.0;
if (0 != a52_frame(fState, (uint8_t *)input, &flags, &level, 0)) {
TRACE("AC3Decoder::DecodeNext: a52_frame failed\n");
return false;
}
TRACE("decoded %d bytes, flags 0x%x\n", bytes, fFlags);
InputRemoveData(bytes);
if (fDisableDynamicCompression)
a52_dynrng(fState, NULL, 0);
return true;
}
}
Decoder *
AC3DecoderPlugin::NewDecoder(uint index)
{
return new AC3Decoder;
}
status_t
AC3DecoderPlugin::GetSupportedFormats(media_format ** formats, size_t * count)
{
static media_format format;
format.type = B_MEDIA_ENCODED_AUDIO;
format.u.encoded_audio = media_encoded_audio_format::wildcard;
*formats = &format;
*count = 1;
media_format_description desc;
desc.family = B_WAV_FORMAT_FAMILY;
desc.u.wav.codec = 0x2000;
BMediaFormats mediaFormats;
return mediaFormats.MakeFormatFor(&desc, 1, &format);
}
MediaPlugin *instantiate_plugin()
{
return new AC3DecoderPlugin;
}
