common/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