Jack2  1.9.12
JackAC3Encoder.cpp
1 /*
2 Copyright (C) 2006 Jesse Chappell <jesse@essej.net> (AC3Jack)
3 Copyright (C) 2012 Grame
4 
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9 
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14 
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 
19 */
20 
21 #include "JackAC3Encoder.h"
22 #include "JackError.h"
23 #include <unistd.h>
24 #include <string.h>
25 #include <stdio.h>
26 
27 #define max(x,y) (((x)>(y)) ? (x) : (y))
28 #define min(x,y) (((x)<(y)) ? (x) : (y))
29 
30 namespace Jack
31 {
32 
33 #ifndef __ppc__
34 
35 JackAC3Encoder::JackAC3Encoder(const JackAC3EncoderParams& params)
36 {
37  aften_set_defaults(&fAftenContext);
38 
39  fAftenContext.channels = params.channels;
40  fAftenContext.samplerate = params.sample_rate;
41  fAftenContext.params.bitrate = params.bitrate;
42 
43  int acmod = A52_ACMOD_MONO;
44  int lfe = params.lfe;
45 
46  switch (params.channels) {
47 
48  case 1: acmod = A52_ACMOD_MONO; break;
49  case 2: acmod = A52_ACMOD_STEREO; break;
50  case 3: acmod = A52_ACMOD_3_0; break;
51  case 4: acmod = A52_ACMOD_2_2; break;
52  case 5: acmod = A52_ACMOD_3_2; break;
53  break;
54 
55  default:
56  break;
57  }
58 
59  if (lfe) {
60  fAftenContext.channels += 1;
61  }
62 
63  fAftenContext.acmod = acmod;
64  fAftenContext.lfe = lfe;
65  fAftenContext.sample_format = A52_SAMPLE_FMT_FLT;
66  fAftenContext.verbose = 1;
67 
68  fAftenContext.system.n_threads = 1;
69 
70  // create interleaved framebuffer for MAX_AC3_CHANNELS
71  fSampleBuffer = new float[MAX_AC3_CHANNELS * A52_SAMPLES_PER_FRAME];
72 
73  // create AC3 buffer
74  fAC3Buffer = new unsigned char[A52_MAX_CODED_FRAME_SIZE];
75  memset(fAC3Buffer, 0, A52_MAX_CODED_FRAME_SIZE);
76 
77  fZeroBuffer = new unsigned char[SPDIF_FRAME_SIZE];
78  memset(fZeroBuffer, 0, SPDIF_FRAME_SIZE);
79 
80  fRingBuffer = jack_ringbuffer_create(32768);
81 
82  fOutSizeByte = 0;
83  fFramePos = 0;
84 
85  fSampleRate = 0;
86  fByteRate = 0;
87 }
88 
89 bool JackAC3Encoder::Init(jack_nframes_t sample_rate)
90 {
91  fSampleRate = sample_rate;
92  fByteRate = fSampleRate * sizeof(short) * 2;
93  return (aften_encode_init(&fAftenContext) == 0);
94 }
95 
96 JackAC3Encoder::~JackAC3Encoder()
97 {
98  aften_encode_close(&fAftenContext);
99 
100  delete [] fSampleBuffer;
101  delete [] fAC3Buffer;
102  delete [] fZeroBuffer;
103 
104  if (fRingBuffer) {
105  jack_ringbuffer_free(fRingBuffer);
106  }
107 }
108 
109 void JackAC3Encoder::Process(float** inputs_buffer, float** outputs_buffer, int nframes)
110 {
111  // fill and process frame buffers as appropriate
112  jack_nframes_t frames_left = A52_SAMPLES_PER_FRAME - fFramePos;
113  jack_nframes_t offset = 0;
114 
115  while (offset < nframes)
116  {
117  if ((nframes - offset) >= frames_left) {
118 
119  // copy only frames_left more data
120  jack_nframes_t pos = fFramePos * fAftenContext.channels;
121  for (jack_nframes_t spos = offset; spos < offset + frames_left; ++spos) {
122  for (size_t i = 0; i < fAftenContext.channels; ++i) {
123  fSampleBuffer[pos + i] = inputs_buffer[i][spos];
124  }
125  pos += fAftenContext.channels;
126  }
127 
128  // use interleaved version
129  int res = aften_encode_frame(&fAftenContext, fAC3Buffer + SPDIF_HEADER_SIZE, fSampleBuffer);
130  if (res < 0) {
131  jack_error("aften_encode_frame error !!");
132  return;
133  }
134 
135  fOutSizeByte = res;
136 
137  FillSpdifHeader(fAC3Buffer, fOutSizeByte + SPDIF_HEADER_SIZE);
138 
139  // push AC3 output to SPDIF ring buffer
140  float calc_ac3byterate = (fOutSizeByte * fSampleRate / (float) A52_SAMPLES_PER_FRAME);
141  jack_nframes_t silencebytes = (jack_nframes_t) (fOutSizeByte * (fByteRate / calc_ac3byterate)) - fOutSizeByte - SPDIF_HEADER_SIZE;
142 
143  jack_ringbuffer_write(fRingBuffer, (const char *)fAC3Buffer, fOutSizeByte + SPDIF_HEADER_SIZE);
144 
145  // write the proper remainder of zero padding (inefficient, should be memsetting)
146  jack_ringbuffer_write(fRingBuffer, (const char *)fZeroBuffer, silencebytes);
147 
148  offset += frames_left;
149  frames_left = A52_SAMPLES_PER_FRAME;
150  fFramePos = 0;
151 
152  } else {
153 
154  // copy incoming data into frame buffers without processing
155  jack_nframes_t pos = fFramePos * fAftenContext.channels;
156  for (jack_nframes_t spos = offset; spos < nframes; ++spos) {
157  for (size_t i = 0; i < fAftenContext.channels; ++i) {
158  fSampleBuffer[pos + i] = inputs_buffer[i][spos];
159  }
160  pos += fAftenContext.channels;
161  }
162 
163  fFramePos += (nframes - offset);
164  offset += (nframes-offset);
165  }
166  }
167 
168  Output2Driver(outputs_buffer, nframes);
169 }
170 
171 void JackAC3Encoder::FillSpdifHeader(unsigned char* buf, int outsize)
172 {
173  // todo, use outsize and not assume the fixed frame size?
174  int ac3outsize = outsize - SPDIF_HEADER_SIZE;
175 
176  buf[0] = 0x72; buf[1] = 0xf8; /* spdif syncword */
177  buf[2] = 0x1f; buf[3] = 0x4e; /* .............. */
178  buf[4] = 0x01; /* AC3 data */
179  buf[5] = buf[13] & 7; /* bsmod, stream = 0 */
180  buf[6] = (ac3outsize << 3) & 0xff;
181  buf[7] = (ac3outsize >> 5) & 0xff;
182 
183 #if !IS_BIGENDIAN
184  swab(buf+SPDIF_HEADER_SIZE, buf + SPDIF_HEADER_SIZE, ac3outsize);
185 #endif
186 }
187 
188 int JackAC3Encoder::Output2Driver(float** outputs, jack_nframes_t nframes)
189 {
190  int wrotebytes = 0;
191  jack_nframes_t nframes_left = nframes;
192 
193  if (jack_ringbuffer_read_space(fRingBuffer) == 0) {
194 
195  // just write silence
196  memset(outputs[0], 0, nframes * sizeof(jack_default_audio_sample_t));
197  memset(outputs[1], 0, nframes * sizeof(jack_default_audio_sample_t));
198 
199  } else {
200 
201  jack_ringbuffer_data_t rb_data[2];
202 
203  jack_ringbuffer_get_read_vector(fRingBuffer, rb_data);
204 
205  while (nframes_left > 0 && rb_data[0].len > 4) {
206 
207  jack_nframes_t towrite_frames = (rb_data[0].len) / (sizeof(short) * 2);
208  towrite_frames = min(towrite_frames, nframes_left);
209 
210  // write and deinterleave into the two channels
211 #if 1
212  sample_move_dS_s16(outputs[0] + (nframes - nframes_left), (char *) rb_data[0].buf, towrite_frames, sizeof(short) * 2);
213  sample_move_dS_s16(outputs[1] + (nframes - nframes_left), (char *) rb_data[0].buf + sizeof(short), towrite_frames, sizeof(short) * 2);
214 #else
215  sample_move_dS_s16_24ph(outputs[0] + (nframes - nframes_left), (char *) rb_data[0].buf, towrite_frames, sizeof(short) * 2);
216  sample_move_dS_s16_24ph(outputs[1] + (nframes - nframes_left), (char *) rb_data[0].buf + sizeof(short), towrite_frames, sizeof(short) * 2);
217 #endif
218  wrotebytes = towrite_frames * sizeof(short) * 2;
219  nframes_left -= towrite_frames;
220 
221  jack_ringbuffer_read_advance(fRingBuffer, wrotebytes);
222  jack_ringbuffer_get_read_vector(fRingBuffer, rb_data);
223  }
224 
225  if (nframes_left > 0) {
226  // write silence
227  memset(outputs[0] + (nframes - nframes_left), 0, (nframes_left) * sizeof(jack_default_audio_sample_t));
228  memset(outputs[1] + (nframes - nframes_left), 0, (nframes_left) * sizeof(jack_default_audio_sample_t));
229  }
230  }
231 
232  return wrotebytes;
233 }
234 
235 void JackAC3Encoder::sample_move_dS_s16(jack_default_audio_sample_t* dst, char *src, jack_nframes_t nsamples, unsigned long src_skip)
236 {
237  /* ALERT: signed sign-extension portability !!! */
238  while (nsamples--) {
239  *dst = (*((short *) src)) / SAMPLE_MAX_16BIT;
240  dst++;
241  src += src_skip;
242  }
243 }
244 
245 void JackAC3Encoder::sample_move_dS_s16_24ph(jack_default_audio_sample_t* dst, char *src, jack_nframes_t nsamples, unsigned long src_skip)
246 {
247  /* ALERT: signed sign-extension portability !!! */
248  while (nsamples--) {
249  *dst = (((int)(*((short *) src))) << 8) / SAMPLE_MAX_24BIT;
250  dst++;
251  src += src_skip;
252  }
253 }
254 
255 void JackAC3Encoder::GetChannelName(const char* name, const char* alias, char* portname, int channel)
256 {
257  /*
258  * 2 channels = L, R
259  * 3 channels = L, C, R
260  * 4 channels = L, R, LS, RS
261  * 5 ch = L, C, R, LS, RS
262  * 6 ch = L, C, R, LS, RS, LFE
263  */
264 
265  const char* AC3_name = "";
266 
267  switch (channel) {
268 
269  case 0:
270  AC3_name = "AC3_1_Left";
271  break;
272 
273  case 1:
274  if (fAftenContext.channels == 2 || fAftenContext.channels == 4) {
275  AC3_name = "AC3_2_Right";
276  } else {
277  AC3_name = "AC3_2_Center";
278  }
279  break;
280 
281  case 2:
282  if (fAftenContext.channels == 4) {
283  AC3_name = "AC3_3_LeftSurround";
284  } else {
285  AC3_name = "AC3_3_Right";
286  }
287  break;
288 
289  case 3:
290  if (fAftenContext.channels == 4) {
291  AC3_name = "AC3_4_RightSurround";
292  } else {
293  AC3_name = "AC3_4_LeftSurround";
294  }
295  break;
296 
297  case 4:
298  if (fAftenContext.channels > 4) {
299  AC3_name = "AC3_5_RightSurround";
300  }
301  break;
302 
303  default:
304  break;
305  }
306 
307  // Last channel
308  if (fAftenContext.lfe && (channel == fAftenContext.channels - 1)) {
309  sprintf(portname, "%s:%s:AC3_%d_LFE", name, alias, fAftenContext.channels);
310  } else {
311  sprintf(portname, "%s:%s:%s", name, alias, AC3_name);
312  }
313 }
314 
315 #endif
316 
317 } // end of namespace
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