winamp/Src/mp3-mpg123/flv_mp3_decoder.cpp

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2024-09-24 12:54:57 +00:00
#include "flv_mp3_decoder.h"
#include "../nsutil/pcm.h"
int FLVDecoderCreator::CreateAudioDecoder(int stereo, int bits, int sample_rate, int format_type, ifc_flvaudiodecoder **decoder)
{
if (format_type == FLV::AUDIO_FORMAT_MP3 || format_type == FLV::AUDIO_FORMAT_MP3_8KHZ)
{
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 (!stereo) {
flags |= MPG123_FORCE_MONO;
}
mpg123_param(ctx, MPG123_FLAGS, flags, 0);
mpg123_param(ctx, MPG123_RVA, MPG123_RVA_OFF, 0);
*decoder = new FLVMP3(ctx);
return CREATEDECODER_SUCCESS;
}
return CREATEDECODER_NOT_MINE;
}
int FLVDecoderCreator::HandlesAudio(int format_type)
{
if (format_type == FLV::AUDIO_FORMAT_MP3 || format_type == FLV::AUDIO_FORMAT_MP3_8KHZ)
{
return CREATEDECODER_SUCCESS;
}
return CREATEDECODER_NOT_MINE;
}
#define CBCLASS FLVDecoderCreator
START_DISPATCH;
CB(CREATE_AUDIO_DECODER, CreateAudioDecoder)
CB(HANDLES_AUDIO, HandlesAudio)
END_DISPATCH;
#undef CBCLASS
/* --- */
#define FHG_DELAY 529
FLVMP3::FLVMP3(mpg123_handle *mp3) : mp3(mp3)
{
mpg123_open_feed(mp3);
bits = 16;
pregap = FHG_DELAY;
max_channels = 2;
channels = 0;
decode_buffer = 0;
decode_buffer_length = 0;
}
FLVMP3::~FLVMP3()
{
if (mp3) {
mpg123_delete(mp3);
mp3 = 0;
}
free(decode_buffer);
}
int FLVMP3::GetOutputFormat(unsigned int *sample_rate, unsigned int *_channels, unsigned int *_bits)
{
mpg123_frameinfo frameInfo;
if (mpg123_info(mp3, &frameInfo) == MPG123_OK)
{
*sample_rate = frameInfo.rate;
channels = (frameInfo.mode == MPG123_M_MONO)?1:2;
*_channels = channels;
*_bits = bits;
return FLV_AUDIO_SUCCESS;
}
else
{
return FLV_AUDIO_FAILURE;
}
}
int FLVMP3::DecodeSample(const void *input_buffer, size_t input_buffer_bytes, void *samples, size_t *samples_size_bytes, double *bitrate)
{
if (!mp3)
return FLV_AUDIO_FAILURE;
mpg123_feed(mp3, (unsigned char *)input_buffer, input_buffer_bytes);
*samples_size_bytes = 0;
*bitrate = 0;
for (;;) {
if (!decode_buffer) {
int channels = 2;
long sample_rate;
int encoding;
if (mpg123_getformat(mp3, &sample_rate, &channels, &encoding) == MPG123_OK) {
this->channels = channels;
decode_buffer_length = sizeof(float) * channels * mpg123_spf(mp3);
decode_buffer = (float *)malloc(decode_buffer_length);
if (!decode_buffer) {
return FLV_AUDIO_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 (!channels) {
long sample_rate = 44100;
int channels = 2;
int encoding = 0;
if (mpg123_getformat(mp3, &sample_rate, &channels, &encoding) == MPG123_OK) {
this->channels = channels;
} else {
return FLV_AUDIO_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(samples, pcm_buf, bits, numSamples);
*samples_size_bytes += numSamples * bits / 8;
samples = (char *)samples + numSamples * bits / 8;
mpg123_frameinfo frameInfo;
if (mpg123_info(mp3, &frameInfo) == MPG123_OK) {
*bitrate = frameInfo.bitrate;
}
return FLV_AUDIO_SUCCESS;
} else if (err == MPG123_NEED_MORE) {
*samples_size_bytes = 0;
return FLV_AUDIO_NEEDS_MORE_INPUT;
} else if (err == MPG123_NEW_FORMAT) {
continue;
} else if (err == MPG123_OK) {
continue;
}
else
return FLV_AUDIO_FAILURE;
}
return FLV_AUDIO_SUCCESS;
}
void FLVMP3::Flush()
{
mpg123_open_feed(mp3);
pregap = FHG_DELAY;
}
void FLVMP3::Close()
{
if (mp3) {
mpg123_delete(mp3);
mp3 = 0;
}
delete this;
}
void FLVMP3::SetPreferences(unsigned int _max_channels, unsigned int preferred_bits)
{
if (preferred_bits)
bits = preferred_bits;
if (max_channels > _max_channels)
max_channels = _max_channels;
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(mp3, MPG123_FLAGS, flags, 0);
mpg123_param(mp3, MPG123_RVA, MPG123_RVA_OFF, 0);
}
#define CBCLASS FLVMP3
START_DISPATCH;
CB(FLV_AUDIO_GETOUTPUTFORMAT, GetOutputFormat)
CB(FLV_AUDIO_DECODE, DecodeSample)
VCB(FLV_AUDIO_FLUSH, Flush)
VCB(FLV_AUDIO_CLOSE, Close)
VCB(FLV_AUDIO_SETPREFERENCES, SetPreferences)
END_DISPATCH;
#undef CBCLASS