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00029 #define DEBUG
00030 #include <limits.h>
00031 #include "avcodec.h"
00032 #include "bitstream.h"
00033 #include "golomb.h"
00034
00035 #define MAX_CHANNELS 8
00036 #define MAX_BLOCKSIZE 65535
00037
00038 #define OUT_BUFFER_SIZE 16384
00039
00040 #define ULONGSIZE 2
00041
00042 #define WAVE_FORMAT_PCM 0x0001
00043
00044 #define DEFAULT_BLOCK_SIZE 256
00045
00046 #define TYPESIZE 4
00047 #define CHANSIZE 0
00048 #define LPCQSIZE 2
00049 #define ENERGYSIZE 3
00050 #define BITSHIFTSIZE 2
00051
00052 #define TYPE_S16HL 3
00053 #define TYPE_S16LH 5
00054
00055 #define NWRAP 3
00056 #define NSKIPSIZE 1
00057
00058 #define LPCQUANT 5
00059 #define V2LPCQOFFSET (1 << LPCQUANT)
00060
00061 #define FNSIZE 2
00062 #define FN_DIFF0 0
00063 #define FN_DIFF1 1
00064 #define FN_DIFF2 2
00065 #define FN_DIFF3 3
00066 #define FN_QUIT 4
00067 #define FN_BLOCKSIZE 5
00068 #define FN_BITSHIFT 6
00069 #define FN_QLPC 7
00070 #define FN_ZERO 8
00071 #define FN_VERBATIM 9
00072
00073 #define VERBATIM_CKSIZE_SIZE 5
00074 #define VERBATIM_BYTE_SIZE 8
00075 #define CANONICAL_HEADER_SIZE 44
00076
00077 typedef struct ShortenContext {
00078 AVCodecContext *avctx;
00079 GetBitContext gb;
00080
00081 int min_framesize, max_framesize;
00082 int channels;
00083
00084 int32_t *decoded[MAX_CHANNELS];
00085 int32_t *offset[MAX_CHANNELS];
00086 uint8_t *bitstream;
00087 int bitstream_size;
00088 int bitstream_index;
00089 unsigned int allocated_bitstream_size;
00090 int header_size;
00091 uint8_t header[OUT_BUFFER_SIZE];
00092 int version;
00093 int cur_chan;
00094 int bitshift;
00095 int nmean;
00096 int internal_ftype;
00097 int nwrap;
00098 int blocksize;
00099 int bitindex;
00100 int32_t lpcqoffset;
00101 } ShortenContext;
00102
00103 static int shorten_decode_init(AVCodecContext * avctx)
00104 {
00105 ShortenContext *s = avctx->priv_data;
00106 s->avctx = avctx;
00107
00108 return 0;
00109 }
00110
00111 static int allocate_buffers(ShortenContext *s)
00112 {
00113 int i, chan;
00114 for (chan=0; chan<s->channels; chan++) {
00115 if(FFMAX(1, s->nmean) >= UINT_MAX/sizeof(int32_t)){
00116 av_log(s->avctx, AV_LOG_ERROR, "nmean too large\n");
00117 return -1;
00118 }
00119 if(s->blocksize + s->nwrap >= UINT_MAX/sizeof(int32_t) || s->blocksize + s->nwrap <= (unsigned)s->nwrap){
00120 av_log(s->avctx, AV_LOG_ERROR, "s->blocksize + s->nwrap too large\n");
00121 return -1;
00122 }
00123
00124 s->offset[chan] = av_realloc(s->offset[chan], sizeof(int32_t)*FFMAX(1, s->nmean));
00125
00126 s->decoded[chan] = av_realloc(s->decoded[chan], sizeof(int32_t)*(s->blocksize + s->nwrap));
00127 for (i=0; i<s->nwrap; i++)
00128 s->decoded[chan][i] = 0;
00129 s->decoded[chan] += s->nwrap;
00130 }
00131 return 0;
00132 }
00133
00134
00135 static inline unsigned int get_uint(ShortenContext *s, int k)
00136 {
00137 if (s->version != 0)
00138 k = get_ur_golomb_shorten(&s->gb, ULONGSIZE);
00139 return get_ur_golomb_shorten(&s->gb, k);
00140 }
00141
00142
00143 static void fix_bitshift(ShortenContext *s, int32_t *buffer)
00144 {
00145 int i;
00146
00147 if (s->bitshift != 0)
00148 for (i = 0; i < s->blocksize; i++)
00149 buffer[s->nwrap + i] <<= s->bitshift;
00150 }
00151
00152
00153 static void init_offset(ShortenContext *s)
00154 {
00155 int32_t mean = 0;
00156 int chan, i;
00157 int nblock = FFMAX(1, s->nmean);
00158
00159 switch (s->internal_ftype)
00160 {
00161 case TYPE_S16HL:
00162 case TYPE_S16LH:
00163 mean = 0;
00164 break;
00165 default:
00166 av_log(s->avctx, AV_LOG_ERROR, "unknown audio type");
00167 abort();
00168 }
00169
00170 for (chan = 0; chan < s->channels; chan++)
00171 for (i = 0; i < nblock; i++)
00172 s->offset[chan][i] = mean;
00173 }
00174
00175 static inline int get_le32(GetBitContext *gb)
00176 {
00177 return bswap_32(get_bits_long(gb, 32));
00178 }
00179
00180 static inline short get_le16(GetBitContext *gb)
00181 {
00182 return bswap_16(get_bits_long(gb, 16));
00183 }
00184
00185 static int decode_wave_header(AVCodecContext *avctx, uint8_t *header, int header_size)
00186 {
00187 GetBitContext hb;
00188 int len;
00189 int chunk_size;
00190 short wave_format;
00191
00192 init_get_bits(&hb, header, header_size*8);
00193 if (get_le32(&hb) != MKTAG('R','I','F','F')) {
00194 av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
00195 return -1;
00196 }
00197
00198 chunk_size = get_le32(&hb);
00199
00200 if (get_le32(&hb) != MKTAG('W','A','V','E')) {
00201 av_log(avctx, AV_LOG_ERROR, "missing WAVE tag\n");
00202 return -1;
00203 }
00204
00205 while (get_le32(&hb) != MKTAG('f','m','t',' ')) {
00206 len = get_le32(&hb);
00207 skip_bits(&hb, 8*len);
00208 }
00209 len = get_le32(&hb);
00210
00211 if (len < 16) {
00212 av_log(avctx, AV_LOG_ERROR, "fmt chunk was too short\n");
00213 return -1;
00214 }
00215
00216 wave_format = get_le16(&hb);
00217
00218 switch (wave_format) {
00219 case WAVE_FORMAT_PCM:
00220 break;
00221 default:
00222 av_log(avctx, AV_LOG_ERROR, "unsupported wave format\n");
00223 return -1;
00224 }
00225
00226 avctx->channels = get_le16(&hb);
00227 avctx->sample_rate = get_le32(&hb);
00228 avctx->bit_rate = get_le32(&hb) * 8;
00229 avctx->block_align = get_le16(&hb);
00230 avctx->bits_per_sample = get_le16(&hb);
00231
00232 if (avctx->bits_per_sample != 16) {
00233 av_log(avctx, AV_LOG_ERROR, "unsupported number of bits per sample\n");
00234 return -1;
00235 }
00236
00237 len -= 16;
00238 if (len > 0)
00239 av_log(avctx, AV_LOG_INFO, "%d header bytes unparsed\n", len);
00240
00241 return 0;
00242 }
00243
00244 static int16_t * interleave_buffer(int16_t *samples, int nchan, int blocksize, int32_t **buffer) {
00245 int i, chan;
00246 for (i=0; i<blocksize; i++)
00247 for (chan=0; chan < nchan; chan++)
00248 *samples++ = FFMIN(buffer[chan][i], 32768);
00249 return samples;
00250 }
00251
00252 static void decode_subframe_lpc(ShortenContext *s, int channel, int residual_size, int pred_order)
00253 {
00254 int sum, i, j;
00255 int coeffs[pred_order];
00256
00257 for (i=0; i<pred_order; i++)
00258 coeffs[i] = get_sr_golomb_shorten(&s->gb, LPCQUANT);
00259
00260 for (i=0; i < s->blocksize; i++) {
00261 sum = s->lpcqoffset;
00262 for (j=0; j<pred_order; j++)
00263 sum += coeffs[j] * s->decoded[channel][i-j-1];
00264 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + (sum >> LPCQUANT);
00265 }
00266 }
00267
00268
00269 static int shorten_decode_frame(AVCodecContext *avctx,
00270 void *data, int *data_size,
00271 const uint8_t *buf, int buf_size)
00272 {
00273 ShortenContext *s = avctx->priv_data;
00274 int i, input_buf_size = 0;
00275 int16_t *samples = data;
00276 if(s->max_framesize == 0){
00277 s->max_framesize= 1024;
00278 s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
00279 }
00280
00281 if(1 && s->max_framesize){
00282 buf_size= FFMIN(buf_size, s->max_framesize - s->bitstream_size);
00283 input_buf_size= buf_size;
00284
00285 if(s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size){
00286
00287 memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
00288 s->bitstream_index=0;
00289 }
00290 memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size);
00291 buf= &s->bitstream[s->bitstream_index];
00292 buf_size += s->bitstream_size;
00293 s->bitstream_size= buf_size;
00294
00295 if(buf_size < s->max_framesize){
00296
00297 *data_size = 0;
00298 return input_buf_size;
00299 }
00300 }
00301 init_get_bits(&s->gb, buf, buf_size*8);
00302 skip_bits(&s->gb, s->bitindex);
00303 if (!s->blocksize)
00304 {
00305 int maxnlpc = 0;
00306
00307 if (get_bits_long(&s->gb, 32) != bswap_32(ff_get_fourcc("ajkg"))) {
00308 av_log(s->avctx, AV_LOG_ERROR, "missing shorten magic 'ajkg'\n");
00309 return -1;
00310 }
00311
00312 s->lpcqoffset = 0;
00313 s->blocksize = DEFAULT_BLOCK_SIZE;
00314 s->channels = 1;
00315 s->nmean = -1;
00316 s->version = get_bits(&s->gb, 8);
00317 s->internal_ftype = get_uint(s, TYPESIZE);
00318
00319 s->channels = get_uint(s, CHANSIZE);
00320 if (s->channels > MAX_CHANNELS) {
00321 av_log(s->avctx, AV_LOG_ERROR, "too many channels: %d\n", s->channels);
00322 return -1;
00323 }
00324
00325
00326 if (s->version > 0) {
00327 int skip_bytes;
00328 s->blocksize = get_uint(s, av_log2(DEFAULT_BLOCK_SIZE));
00329 maxnlpc = get_uint(s, LPCQSIZE);
00330 s->nmean = get_uint(s, 0);
00331
00332 skip_bytes = get_uint(s, NSKIPSIZE);
00333 for (i=0; i<skip_bytes; i++) {
00334 skip_bits(&s->gb, 8);
00335 }
00336 }
00337 s->nwrap = FFMAX(NWRAP, maxnlpc);
00338
00339 if (allocate_buffers(s))
00340 return -1;
00341
00342 init_offset(s);
00343
00344 if (s->version > 1)
00345 s->lpcqoffset = V2LPCQOFFSET;
00346
00347 if (get_ur_golomb_shorten(&s->gb, FNSIZE) != FN_VERBATIM) {
00348 av_log(s->avctx, AV_LOG_ERROR, "missing verbatim section at beginning of stream\n");
00349 return -1;
00350 }
00351
00352 s->header_size = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
00353 if (s->header_size >= OUT_BUFFER_SIZE || s->header_size < CANONICAL_HEADER_SIZE) {
00354 av_log(s->avctx, AV_LOG_ERROR, "header is wrong size: %d\n", s->header_size);
00355 return -1;
00356 }
00357
00358 for (i=0; i<s->header_size; i++)
00359 s->header[i] = (char)get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
00360
00361 if (decode_wave_header(avctx, s->header, s->header_size) < 0)
00362 return -1;
00363
00364 s->cur_chan = 0;
00365 s->bitshift = 0;
00366 }
00367 else
00368 {
00369 int cmd;
00370 int len;
00371 cmd = get_ur_golomb_shorten(&s->gb, FNSIZE);
00372 switch (cmd) {
00373 case FN_ZERO:
00374 case FN_DIFF0:
00375 case FN_DIFF1:
00376 case FN_DIFF2:
00377 case FN_DIFF3:
00378 case FN_QLPC:
00379 {
00380 int residual_size = 0;
00381 int channel = s->cur_chan;
00382 int32_t coffset;
00383 if (cmd != FN_ZERO) {
00384 residual_size = get_ur_golomb_shorten(&s->gb, ENERGYSIZE);
00385
00386 if (s->version == 0)
00387 residual_size--;
00388 }
00389
00390 if (s->nmean == 0)
00391 coffset = s->offset[channel][0];
00392 else {
00393 int32_t sum = (s->version < 2) ? 0 : s->nmean / 2;
00394 for (i=0; i<s->nmean; i++)
00395 sum += s->offset[channel][i];
00396 coffset = sum / s->nmean;
00397 if (s->version >= 2)
00398 coffset >>= FFMIN(1, s->bitshift);
00399 }
00400 switch (cmd) {
00401 case FN_ZERO:
00402 for (i=0; i<s->blocksize; i++)
00403 s->decoded[channel][i] = 0;
00404 break;
00405 case FN_DIFF0:
00406 for (i=0; i<s->blocksize; i++)
00407 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + coffset;
00408 break;
00409 case FN_DIFF1:
00410 for (i=0; i<s->blocksize; i++)
00411 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + s->decoded[channel][i - 1];
00412 break;
00413 case FN_DIFF2:
00414 for (i=0; i<s->blocksize; i++)
00415 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 2*s->decoded[channel][i-1]
00416 - s->decoded[channel][i-2];
00417 break;
00418 case FN_DIFF3:
00419 for (i=0; i<s->blocksize; i++)
00420 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 3*s->decoded[channel][i-1]
00421 - 3*s->decoded[channel][i-2]
00422 + s->decoded[channel][i-3];
00423 break;
00424 case FN_QLPC:
00425 {
00426 int pred_order = get_ur_golomb_shorten(&s->gb, LPCQSIZE);
00427 for (i=0; i<pred_order; i++)
00428 s->decoded[channel][i - pred_order] -= coffset;
00429 decode_subframe_lpc(s, channel, residual_size, pred_order);
00430 if (coffset != 0)
00431 for (i=0; i < s->blocksize; i++)
00432 s->decoded[channel][i] += coffset;
00433 }
00434 }
00435 if (s->nmean > 0) {
00436 int32_t sum = (s->version < 2) ? 0 : s->blocksize / 2;
00437 for (i=0; i<s->blocksize; i++)
00438 sum += s->decoded[channel][i];
00439
00440 for (i=1; i<s->nmean; i++)
00441 s->offset[channel][i-1] = s->offset[channel][i];
00442
00443 if (s->version < 2)
00444 s->offset[channel][s->nmean - 1] = sum / s->blocksize;
00445 else
00446 s->offset[channel][s->nmean - 1] = (sum / s->blocksize) << s->bitshift;
00447 }
00448 for (i=-s->nwrap; i<0; i++)
00449 s->decoded[channel][i] = s->decoded[channel][i + s->blocksize];
00450
00451 fix_bitshift(s, s->decoded[channel]);
00452
00453 s->cur_chan++;
00454 if (s->cur_chan == s->channels) {
00455 samples = interleave_buffer(samples, s->channels, s->blocksize, s->decoded);
00456 s->cur_chan = 0;
00457 goto frame_done;
00458 }
00459 break;
00460 }
00461 break;
00462 case FN_VERBATIM:
00463 len = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
00464 while (len--) {
00465 get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
00466 }
00467 break;
00468 case FN_BITSHIFT:
00469 s->bitshift = get_ur_golomb_shorten(&s->gb, BITSHIFTSIZE);
00470 break;
00471 case FN_BLOCKSIZE:
00472 s->blocksize = get_uint(s, av_log2(s->blocksize));
00473 break;
00474 case FN_QUIT:
00475 *data_size = 0;
00476 return buf_size;
00477 break;
00478 default:
00479 av_log(avctx, AV_LOG_ERROR, "unknown shorten function %d\n", cmd);
00480 return -1;
00481 break;
00482 }
00483 }
00484 frame_done:
00485 *data_size = (int8_t *)samples - (int8_t *)data;
00486
00487
00488 s->bitindex = get_bits_count(&s->gb) - 8*((get_bits_count(&s->gb))/8);
00489 i= (get_bits_count(&s->gb))/8;
00490 if (i > buf_size) {
00491 av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
00492 s->bitstream_size=0;
00493 s->bitstream_index=0;
00494 return -1;
00495 }
00496 if (s->bitstream_size) {
00497 s->bitstream_index += i;
00498 s->bitstream_size -= i;
00499 return input_buf_size;
00500 } else
00501 return i;
00502 }
00503
00504 static int shorten_decode_close(AVCodecContext *avctx)
00505 {
00506 ShortenContext *s = avctx->priv_data;
00507 int i;
00508
00509 for (i = 0; i < s->channels; i++) {
00510 s->decoded[i] -= s->nwrap;
00511 av_freep(&s->decoded[i]);
00512 av_freep(&s->offset[i]);
00513 }
00514 av_freep(&s->bitstream);
00515 return 0;
00516 }
00517
00518 static void shorten_flush(AVCodecContext *avctx){
00519 ShortenContext *s = avctx->priv_data;
00520
00521 s->bitstream_size=
00522 s->bitstream_index= 0;
00523 }
00524
00525 AVCodec shorten_decoder = {
00526 "shorten",
00527 CODEC_TYPE_AUDIO,
00528 CODEC_ID_SHORTEN,
00529 sizeof(ShortenContext),
00530 shorten_decode_init,
00531 NULL,
00532 shorten_decode_close,
00533 shorten_decode_frame,
00534 .flush= shorten_flush,
00535 };