winamp/Src/mp3-mpg123/mkv_mp3_decoder.cpp
2024-09-24 14:54:57 +02:00

169 lines
4.2 KiB
C++

#include "mkv_mp3_decoder.h"
#include "../nsutil/pcm.h"
int MKVDecoder::CreateAudioDecoder(const char *codec_id, const nsmkv::TrackEntryData *track_entry_data, const nsmkv::AudioData *audio_data, unsigned int preferred_bits, unsigned int max_channels,bool floating_point, ifc_mkvaudiodecoder **decoder)
{
if (!strcmp(codec_id, "A_MPEG/L3")
|| !strcmp(codec_id, "A_MPEG/L2")
|| !strcmp(codec_id, "A_MPEG/L1"))
{
mpg123_handle *ctx = mpg123_new(NULL, NULL);
if (!ctx)
return CREATEDECODER_FAILURE;
long flags = MPG123_QUIET|MPG123_FORCE_FLOAT|MPG123_SKIP_ID3V2|MPG123_IGNORE_STREAMLENGTH|MPG123_IGNORE_INFOFRAME;
if (max_channels == 1) {
flags |= MPG123_FORCE_MONO;
}
mpg123_param(ctx, MPG123_FLAGS, flags, 0);
mpg123_param(ctx, MPG123_RVA, MPG123_RVA_OFF, 0);
*decoder = new MKVMP3Decoder(ctx, preferred_bits, max_channels, floating_point);
return CREATEDECODER_SUCCESS;
}
return CREATEDECODER_NOT_MINE;
}
#define CBCLASS MKVDecoder
START_DISPATCH;
CB(CREATE_AUDIO_DECODER, CreateAudioDecoder)
END_DISPATCH;
#undef CBCLASS
#define FHG_DELAY 529
MKVMP3Decoder::MKVMP3Decoder(mpg123_handle *mp3, unsigned int bps, unsigned max_channels, bool floating_point)
: mp3(mp3), bits(bps?bps:16), max_channels(max_channels?max_channels:2), floating_point(floating_point)
{
decode_buffer=0;
decode_buffer_length=0;
sample_rate = 0;
channels = 0;
pregap = FHG_DELAY;
mpg123_open_feed(mp3);
}
MKVMP3Decoder::~MKVMP3Decoder()
{
if (mp3) {
mpg123_delete(mp3);
mp3 = 0;
}
free(decode_buffer);
}
bool MKVMP3Decoder::_UpdateProperties()
{
if (mp3 && (!channels || !sample_rate)) {
long sample_rate = 44100;
int channels = 2;
int encoding = 0;
if (mpg123_getformat(mp3, &sample_rate, &channels, &encoding) == MPG123_OK) {
this->channels = channels;
this->sample_rate = sample_rate;
}
}
return channels && sample_rate;
}
int MKVMP3Decoder::OutputFrameSize(size_t *frame_size)
{
if (_UpdateProperties()) {
*frame_size = (bits/8) * channels * mpg123_spf(mp3);
return MKV_SUCCESS;
} else {
return MKV_FAILURE;
}
}
int MKVMP3Decoder::GetOutputProperties(unsigned int *sampleRate, unsigned int *channels, unsigned int *bitsPerSample, bool *isFloat)
{
if (_UpdateProperties()) {
*sampleRate = this->sample_rate;
*channels = this->channels;
*bitsPerSample = bits;
*isFloat = floating_point;
return MKV_SUCCESS;
}
else
{
return MKV_FAILURE;
}
}
int MKVMP3Decoder::DecodeBlock(void *inputBuffer, size_t inputBufferBytes, void *outputBuffer, size_t *outputBufferBytes)
{
if (!mp3)
return MKV_FAILURE;
*outputBufferBytes = 0;
mpg123_feed(mp3, (unsigned char *)inputBuffer, inputBufferBytes);
for (;;) {
if (!decode_buffer) {
if (_UpdateProperties()) {
decode_buffer_length = sizeof(float) * channels * mpg123_spf(mp3);
decode_buffer = (float *)malloc(decode_buffer_length);
if (!decode_buffer) {
return MKV_FAILURE;
}
}
}
// get the decoded data out
size_t pcm_buf_used=0;
int err = mpg123_read(mp3, (unsigned char *)decode_buffer, decode_buffer_length, &pcm_buf_used);
if (pcm_buf_used) {
if (!_UpdateProperties()) {
return MKV_FAILURE;
}
// deal with pregap
size_t numSamples = pcm_buf_used / sizeof(float);
size_t offset = min(numSamples, pregap * channels);
numSamples -= offset;
pregap -= (int)offset / channels;
float *pcm_buf = decode_buffer + offset;
// convert to destination sample format
nsutil_pcm_FloatToInt_Interleaved(outputBuffer, pcm_buf, bits, numSamples);
*outputBufferBytes += numSamples * bits / 8;
outputBuffer = (char *)outputBuffer + numSamples * bits / 8;
return MKV_SUCCESS;
} else if (err == MPG123_NEED_MORE) {
*outputBufferBytes = 0;
return MKV_NEED_MORE_INPUT;
} else if (err == MPG123_NEW_FORMAT) {
continue;
} else if (err == MPG123_OK) {
continue;
}
else
return MKV_FAILURE;
}
return MKV_SUCCESS;
}
void MKVMP3Decoder::Flush()
{
mpg123_open_feed(mp3);
pregap = FHG_DELAY;
}
void MKVMP3Decoder::Close()
{
delete this;
}
#define CBCLASS MKVMP3Decoder
START_DISPATCH;
CB(OUTPUT_FRAME_SIZE, OutputFrameSize)
CB(GET_OUTPUT_PROPERTIES, GetOutputProperties)
CB(DECODE_BLOCK, DecodeBlock)
VCB(FLUSH, Flush)
VCB(CLOSE, Close)
END_DISPATCH;
#undef CBCLASS