JackAC3Encoder.cpp
/*
Copyright (C) 2006 Jesse Chappell <jesse@essej.net> (AC3Jack)
Copyright (C) 2012 Grame
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "JackAC3Encoder.h"
#include "JackError.h"
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#define max(x,y) (((x)>(y)) ? (x) : (y))
#define min(x,y) (((x)<(y)) ? (x) : (y))
namespace Jack
{
#ifndef __ppc__
JackAC3Encoder::JackAC3Encoder(const JackAC3EncoderParams& params)
{
aften_set_defaults(&fAftenContext);
fAftenContext.channels = params.channels;
fAftenContext.samplerate = params.sample_rate;
fAftenContext.params.bitrate = params.bitrate;
int acmod = A52_ACMOD_MONO;
int lfe = params.lfe;
switch (params.channels) {
case 1: acmod = A52_ACMOD_MONO; break;
case 2: acmod = A52_ACMOD_STEREO; break;
case 3: acmod = A52_ACMOD_3_0; break;
case 4: acmod = A52_ACMOD_2_2; break;
case 5: acmod = A52_ACMOD_3_2; break;
break;
default:
break;
}
if (lfe) {
fAftenContext.channels += 1;
}
fAftenContext.acmod = acmod;
fAftenContext.lfe = lfe;
fAftenContext.sample_format = A52_SAMPLE_FMT_FLT;
fAftenContext.verbose = 1;
fAftenContext.system.n_threads = 1;
// create interleaved framebuffer for MAX_AC3_CHANNELS
fSampleBuffer = new float[MAX_AC3_CHANNELS * A52_SAMPLES_PER_FRAME];
// create AC3 buffer
fAC3Buffer = new unsigned char[A52_MAX_CODED_FRAME_SIZE];
memset(fAC3Buffer, 0, A52_MAX_CODED_FRAME_SIZE);
fZeroBuffer = new unsigned char[SPDIF_FRAME_SIZE];
memset(fZeroBuffer, 0, SPDIF_FRAME_SIZE);
fRingBuffer = jack_ringbuffer_create(32768);
fOutSizeByte = 0;
fFramePos = 0;
fSampleRate = 0;
fByteRate = 0;
}
bool JackAC3Encoder::Init(jack_nframes_t sample_rate)
{
fSampleRate = sample_rate;
fByteRate = fSampleRate * sizeof(short) * 2;
return (aften_encode_init(&fAftenContext) == 0);
}
JackAC3Encoder::~JackAC3Encoder()
{
aften_encode_close(&fAftenContext);
delete [] fSampleBuffer;
delete [] fAC3Buffer;
delete [] fZeroBuffer;
if (fRingBuffer) {
jack_ringbuffer_free(fRingBuffer);
}
}
void JackAC3Encoder::Process(float** inputs_buffer, float** outputs_buffer, int nframes)
{
// fill and process frame buffers as appropriate
jack_nframes_t frames_left = A52_SAMPLES_PER_FRAME - fFramePos;
jack_nframes_t offset = 0;
while (offset < nframes)
{
if ((nframes - offset) >= frames_left) {
// copy only frames_left more data
jack_nframes_t pos = fFramePos * fAftenContext.channels;
for (jack_nframes_t spos = offset; spos < offset + frames_left; ++spos) {
for (size_t i = 0; i < fAftenContext.channels; ++i) {
fSampleBuffer[pos + i] = inputs_buffer[i][spos];
}
pos += fAftenContext.channels;
}
// use interleaved version
int res = aften_encode_frame(&fAftenContext, fAC3Buffer + SPDIF_HEADER_SIZE, fSampleBuffer);
if (res < 0) {
jack_error("aften_encode_frame error !!");
return;
}
fOutSizeByte = res;
FillSpdifHeader(fAC3Buffer, fOutSizeByte + SPDIF_HEADER_SIZE);
// push AC3 output to SPDIF ring buffer
float calc_ac3byterate = (fOutSizeByte * fSampleRate / (float) A52_SAMPLES_PER_FRAME);
jack_nframes_t silencebytes = (jack_nframes_t) (fOutSizeByte * (fByteRate / calc_ac3byterate)) - fOutSizeByte - SPDIF_HEADER_SIZE;
jack_ringbuffer_write(fRingBuffer, (const char *)fAC3Buffer, fOutSizeByte + SPDIF_HEADER_SIZE);
// write the proper remainder of zero padding (inefficient, should be memsetting)
jack_ringbuffer_write(fRingBuffer, (const char *)fZeroBuffer, silencebytes);
offset += frames_left;
frames_left = A52_SAMPLES_PER_FRAME;
fFramePos = 0;
} else {
// copy incoming data into frame buffers without processing
jack_nframes_t pos = fFramePos * fAftenContext.channels;
for (jack_nframes_t spos = offset; spos < nframes; ++spos) {
for (size_t i = 0; i < fAftenContext.channels; ++i) {
fSampleBuffer[pos + i] = inputs_buffer[i][spos];
}
pos += fAftenContext.channels;
}
fFramePos += (nframes - offset);
offset += (nframes-offset);
}
}
Output2Driver(outputs_buffer, nframes);
}
void JackAC3Encoder::FillSpdifHeader(unsigned char* buf, int outsize)
{
// todo, use outsize and not assume the fixed frame size?
int ac3outsize = outsize - SPDIF_HEADER_SIZE;
buf[0] = 0x72; buf[1] = 0xf8; /* spdif syncword */
buf[2] = 0x1f; buf[3] = 0x4e; /* .............. */
buf[4] = 0x01; /* AC3 data */
buf[5] = buf[13] & 7; /* bsmod, stream = 0 */
buf[6] = (ac3outsize << 3) & 0xff;
buf[7] = (ac3outsize >> 5) & 0xff;
#if !IS_BIGENDIAN
swab(buf+SPDIF_HEADER_SIZE, buf + SPDIF_HEADER_SIZE, ac3outsize);
#endif
}
int JackAC3Encoder::Output2Driver(float** outputs, jack_nframes_t nframes)
{
int wrotebytes = 0;
jack_nframes_t nframes_left = nframes;
if (jack_ringbuffer_read_space(fRingBuffer) == 0) {
// just write silence
memset(outputs[0], 0, nframes * sizeof(jack_default_audio_sample_t));
memset(outputs[1], 0, nframes * sizeof(jack_default_audio_sample_t));
} else {
jack_ringbuffer_data_t rb_data[2];
jack_ringbuffer_get_read_vector(fRingBuffer, rb_data);
while (nframes_left > 0 && rb_data[0].len > 4) {
jack_nframes_t towrite_frames = (rb_data[0].len) / (sizeof(short) * 2);
towrite_frames = min(towrite_frames, nframes_left);
// write and deinterleave into the two channels
#if 1
sample_move_dS_s16(outputs[0] + (nframes - nframes_left), (char *) rb_data[0].buf, towrite_frames, sizeof(short) * 2);
sample_move_dS_s16(outputs[1] + (nframes - nframes_left), (char *) rb_data[0].buf + sizeof(short), towrite_frames, sizeof(short) * 2);
#else
sample_move_dS_s16_24ph(outputs[0] + (nframes - nframes_left), (char *) rb_data[0].buf, towrite_frames, sizeof(short) * 2);
sample_move_dS_s16_24ph(outputs[1] + (nframes - nframes_left), (char *) rb_data[0].buf + sizeof(short), towrite_frames, sizeof(short) * 2);
#endif
wrotebytes = towrite_frames * sizeof(short) * 2;
nframes_left -= towrite_frames;
jack_ringbuffer_read_advance(fRingBuffer, wrotebytes);
jack_ringbuffer_get_read_vector(fRingBuffer, rb_data);
}
if (nframes_left > 0) {
// write silence
memset(outputs[0] + (nframes - nframes_left), 0, (nframes_left) * sizeof(jack_default_audio_sample_t));
memset(outputs[1] + (nframes - nframes_left), 0, (nframes_left) * sizeof(jack_default_audio_sample_t));
}
}
return wrotebytes;
}
void JackAC3Encoder::sample_move_dS_s16(jack_default_audio_sample_t* dst, char *src, jack_nframes_t nsamples, unsigned long src_skip)
{
/* ALERT: signed sign-extension portability !!! */
while (nsamples--) {
*dst = (*((short *) src)) / SAMPLE_MAX_16BIT;
dst++;
src += src_skip;
}
}
void JackAC3Encoder::sample_move_dS_s16_24ph(jack_default_audio_sample_t* dst, char *src, jack_nframes_t nsamples, unsigned long src_skip)
{
/* ALERT: signed sign-extension portability !!! */
while (nsamples--) {
*dst = (((int)(*((short *) src))) << 8) / SAMPLE_MAX_24BIT;
dst++;
src += src_skip;
}
}
void JackAC3Encoder::GetChannelName(const char* name, const char* alias, char* portname, int channel)
{
/*
* 2 channels = L, R
* 3 channels = L, C, R
* 4 channels = L, R, LS, RS
* 5 ch = L, C, R, LS, RS
* 6 ch = L, C, R, LS, RS, LFE
*/
const char* AC3_name = "";
switch (channel) {
case 0:
AC3_name = "AC3_1_Left";
break;
case 1:
if (fAftenContext.channels == 2 || fAftenContext.channels == 4) {
AC3_name = "AC3_2_Right";
} else {
AC3_name = "AC3_2_Center";
}
break;
case 2:
if (fAftenContext.channels == 4) {
AC3_name = "AC3_3_LeftSurround";
} else {
AC3_name = "AC3_3_Right";
}
break;
case 3:
if (fAftenContext.channels == 4) {
AC3_name = "AC3_4_RightSurround";
} else {
AC3_name = "AC3_4_LeftSurround";
}
break;
case 4:
if (fAftenContext.channels > 4) {
AC3_name = "AC3_5_RightSurround";
}
break;
default:
break;
}
// Last channel
if (fAftenContext.lfe && (channel == fAftenContext.channels - 1)) {
sprintf(portname, "%s:%s:AC3_%d_LFE", name, alias, fAftenContext.channels);
} else {
sprintf(portname, "%s:%s:%s", name, alias, AC3_name);
}
}
#endif
} // end of namespace
jack_ringbuffer_read_space
size_t jack_ringbuffer_read_space(const jack_ringbuffer_t *rb)
Jack
Definition: JackAC3Encoder.cpp:30
jack_ringbuffer_create
jack_ringbuffer_t * jack_ringbuffer_create(size_t sz)
jack_error
SERVER_EXPORT void jack_error(const char *fmt,...)
Definition: JackError.cpp:92
jack_ringbuffer_free
void jack_ringbuffer_free(jack_ringbuffer_t *rb)
jack_ringbuffer_get_read_vector
void jack_ringbuffer_get_read_vector(const jack_ringbuffer_t *rb, jack_ringbuffer_data_t *vec)
jack_ringbuffer_write
size_t jack_ringbuffer_write(jack_ringbuffer_t *rb, const char *src, size_t cnt)
jack_ringbuffer_read_advance
void jack_ringbuffer_read_advance(jack_ringbuffer_t *rb, size_t cnt)
jack_ringbuffer_data_t
Definition: ringbuffer.h:45