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00029 #define DEBUG
00030 #include <limits.h>
00031 #include "avcodec.h"
00032 #include "get_bits.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 int *coeffs;
00087 uint8_t *bitstream;
00088 int bitstream_size;
00089 int bitstream_index;
00090 unsigned int allocated_bitstream_size;
00091 int header_size;
00092 uint8_t header[OUT_BUFFER_SIZE];
00093 int version;
00094 int cur_chan;
00095 int bitshift;
00096 int nmean;
00097 int internal_ftype;
00098 int nwrap;
00099 int blocksize;
00100 int bitindex;
00101 int32_t lpcqoffset;
00102 } ShortenContext;
00103
00104 static av_cold int shorten_decode_init(AVCodecContext * avctx)
00105 {
00106 ShortenContext *s = avctx->priv_data;
00107 s->avctx = avctx;
00108 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00109
00110 return 0;
00111 }
00112
00113 static int allocate_buffers(ShortenContext *s)
00114 {
00115 int i, chan;
00116 int *coeffs;
00117
00118 for (chan=0; chan<s->channels; chan++) {
00119 if(FFMAX(1, s->nmean) >= UINT_MAX/sizeof(int32_t)){
00120 av_log(s->avctx, AV_LOG_ERROR, "nmean too large\n");
00121 return -1;
00122 }
00123 if(s->blocksize + s->nwrap >= UINT_MAX/sizeof(int32_t) || s->blocksize + s->nwrap <= (unsigned)s->nwrap){
00124 av_log(s->avctx, AV_LOG_ERROR, "s->blocksize + s->nwrap too large\n");
00125 return -1;
00126 }
00127
00128 s->offset[chan] = av_realloc(s->offset[chan], sizeof(int32_t)*FFMAX(1, s->nmean));
00129
00130 s->decoded[chan] = av_realloc(s->decoded[chan], sizeof(int32_t)*(s->blocksize + s->nwrap));
00131 for (i=0; i<s->nwrap; i++)
00132 s->decoded[chan][i] = 0;
00133 s->decoded[chan] += s->nwrap;
00134 }
00135
00136 coeffs = av_realloc(s->coeffs, s->nwrap * sizeof(*s->coeffs));
00137 if (!coeffs)
00138 return AVERROR(ENOMEM);
00139 s->coeffs = coeffs;
00140
00141 return 0;
00142 }
00143
00144
00145 static inline unsigned int get_uint(ShortenContext *s, int k)
00146 {
00147 if (s->version != 0)
00148 k = get_ur_golomb_shorten(&s->gb, ULONGSIZE);
00149 return get_ur_golomb_shorten(&s->gb, k);
00150 }
00151
00152
00153 static void fix_bitshift(ShortenContext *s, int32_t *buffer)
00154 {
00155 int i;
00156
00157 if (s->bitshift != 0)
00158 for (i = 0; i < s->blocksize; i++)
00159 buffer[s->nwrap + i] <<= s->bitshift;
00160 }
00161
00162
00163 static void init_offset(ShortenContext *s)
00164 {
00165 int32_t mean = 0;
00166 int chan, i;
00167 int nblock = FFMAX(1, s->nmean);
00168
00169 switch (s->internal_ftype)
00170 {
00171 case TYPE_S16HL:
00172 case TYPE_S16LH:
00173 mean = 0;
00174 break;
00175 default:
00176 av_log(s->avctx, AV_LOG_ERROR, "unknown audio type");
00177 abort();
00178 }
00179
00180 for (chan = 0; chan < s->channels; chan++)
00181 for (i = 0; i < nblock; i++)
00182 s->offset[chan][i] = mean;
00183 }
00184
00185 static inline int get_le32(GetBitContext *gb)
00186 {
00187 return av_bswap32(get_bits_long(gb, 32));
00188 }
00189
00190 static inline short get_le16(GetBitContext *gb)
00191 {
00192 return av_bswap16(get_bits_long(gb, 16));
00193 }
00194
00195 static int decode_wave_header(AVCodecContext *avctx, uint8_t *header, int header_size)
00196 {
00197 GetBitContext hb;
00198 int len;
00199 int chunk_size;
00200 short wave_format;
00201
00202 init_get_bits(&hb, header, header_size*8);
00203 if (get_le32(&hb) != MKTAG('R','I','F','F')) {
00204 av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
00205 return -1;
00206 }
00207
00208 chunk_size = get_le32(&hb);
00209
00210 if (get_le32(&hb) != MKTAG('W','A','V','E')) {
00211 av_log(avctx, AV_LOG_ERROR, "missing WAVE tag\n");
00212 return -1;
00213 }
00214
00215 while (get_le32(&hb) != MKTAG('f','m','t',' ')) {
00216 len = get_le32(&hb);
00217 skip_bits(&hb, 8*len);
00218 }
00219 len = get_le32(&hb);
00220
00221 if (len < 16) {
00222 av_log(avctx, AV_LOG_ERROR, "fmt chunk was too short\n");
00223 return -1;
00224 }
00225
00226 wave_format = get_le16(&hb);
00227
00228 switch (wave_format) {
00229 case WAVE_FORMAT_PCM:
00230 break;
00231 default:
00232 av_log(avctx, AV_LOG_ERROR, "unsupported wave format\n");
00233 return -1;
00234 }
00235
00236 avctx->channels = get_le16(&hb);
00237 avctx->sample_rate = get_le32(&hb);
00238 avctx->bit_rate = get_le32(&hb) * 8;
00239 avctx->block_align = get_le16(&hb);
00240 avctx->bits_per_coded_sample = get_le16(&hb);
00241
00242 if (avctx->bits_per_coded_sample != 16) {
00243 av_log(avctx, AV_LOG_ERROR, "unsupported number of bits per sample\n");
00244 return -1;
00245 }
00246
00247 len -= 16;
00248 if (len > 0)
00249 av_log(avctx, AV_LOG_INFO, "%d header bytes unparsed\n", len);
00250
00251 return 0;
00252 }
00253
00254 static int16_t * interleave_buffer(int16_t *samples, int nchan, int blocksize, int32_t **buffer) {
00255 int i, chan;
00256 for (i=0; i<blocksize; i++)
00257 for (chan=0; chan < nchan; chan++)
00258 *samples++ = FFMIN(buffer[chan][i], 32768);
00259 return samples;
00260 }
00261
00262 static void decode_subframe_lpc(ShortenContext *s, int channel, int residual_size, int pred_order)
00263 {
00264 int sum, i, j;
00265 int *coeffs = s->coeffs;
00266
00267 for (i=0; i<pred_order; i++)
00268 coeffs[i] = get_sr_golomb_shorten(&s->gb, LPCQUANT);
00269
00270 for (i=0; i < s->blocksize; i++) {
00271 sum = s->lpcqoffset;
00272 for (j=0; j<pred_order; j++)
00273 sum += coeffs[j] * s->decoded[channel][i-j-1];
00274 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + (sum >> LPCQUANT);
00275 }
00276 }
00277
00278
00279 static int shorten_decode_frame(AVCodecContext *avctx,
00280 void *data, int *data_size,
00281 AVPacket *avpkt)
00282 {
00283 const uint8_t *buf = avpkt->data;
00284 int buf_size = avpkt->size;
00285 ShortenContext *s = avctx->priv_data;
00286 int i, input_buf_size = 0;
00287 int16_t *samples = data;
00288 if(s->max_framesize == 0){
00289 s->max_framesize= 1024;
00290 s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
00291 }
00292
00293 if(1 && s->max_framesize){
00294 buf_size= FFMIN(buf_size, s->max_framesize - s->bitstream_size);
00295 input_buf_size= buf_size;
00296
00297 if(s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size){
00298
00299 memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
00300 s->bitstream_index=0;
00301 }
00302 memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size);
00303 buf= &s->bitstream[s->bitstream_index];
00304 buf_size += s->bitstream_size;
00305 s->bitstream_size= buf_size;
00306
00307 if(buf_size < s->max_framesize){
00308
00309 *data_size = 0;
00310 return input_buf_size;
00311 }
00312 }
00313 init_get_bits(&s->gb, buf, buf_size*8);
00314 skip_bits(&s->gb, s->bitindex);
00315 if (!s->blocksize)
00316 {
00317 int maxnlpc = 0;
00318
00319 if (get_bits_long(&s->gb, 32) != AV_RB32("ajkg")) {
00320 av_log(s->avctx, AV_LOG_ERROR, "missing shorten magic 'ajkg'\n");
00321 return -1;
00322 }
00323
00324 s->lpcqoffset = 0;
00325 s->blocksize = DEFAULT_BLOCK_SIZE;
00326 s->channels = 1;
00327 s->nmean = -1;
00328 s->version = get_bits(&s->gb, 8);
00329 s->internal_ftype = get_uint(s, TYPESIZE);
00330
00331 s->channels = get_uint(s, CHANSIZE);
00332 if (s->channels > MAX_CHANNELS) {
00333 av_log(s->avctx, AV_LOG_ERROR, "too many channels: %d\n", s->channels);
00334 return -1;
00335 }
00336
00337
00338 if (s->version > 0) {
00339 int skip_bytes;
00340 s->blocksize = get_uint(s, av_log2(DEFAULT_BLOCK_SIZE));
00341 maxnlpc = get_uint(s, LPCQSIZE);
00342 s->nmean = get_uint(s, 0);
00343
00344 skip_bytes = get_uint(s, NSKIPSIZE);
00345 for (i=0; i<skip_bytes; i++) {
00346 skip_bits(&s->gb, 8);
00347 }
00348 }
00349 s->nwrap = FFMAX(NWRAP, maxnlpc);
00350
00351 if (allocate_buffers(s))
00352 return -1;
00353
00354 init_offset(s);
00355
00356 if (s->version > 1)
00357 s->lpcqoffset = V2LPCQOFFSET;
00358
00359 if (get_ur_golomb_shorten(&s->gb, FNSIZE) != FN_VERBATIM) {
00360 av_log(s->avctx, AV_LOG_ERROR, "missing verbatim section at beginning of stream\n");
00361 return -1;
00362 }
00363
00364 s->header_size = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
00365 if (s->header_size >= OUT_BUFFER_SIZE || s->header_size < CANONICAL_HEADER_SIZE) {
00366 av_log(s->avctx, AV_LOG_ERROR, "header is wrong size: %d\n", s->header_size);
00367 return -1;
00368 }
00369
00370 for (i=0; i<s->header_size; i++)
00371 s->header[i] = (char)get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
00372
00373 if (decode_wave_header(avctx, s->header, s->header_size) < 0)
00374 return -1;
00375
00376 s->cur_chan = 0;
00377 s->bitshift = 0;
00378 }
00379 else
00380 {
00381 int cmd;
00382 int len;
00383 cmd = get_ur_golomb_shorten(&s->gb, FNSIZE);
00384 switch (cmd) {
00385 case FN_ZERO:
00386 case FN_DIFF0:
00387 case FN_DIFF1:
00388 case FN_DIFF2:
00389 case FN_DIFF3:
00390 case FN_QLPC:
00391 {
00392 int residual_size = 0;
00393 int channel = s->cur_chan;
00394 int32_t coffset;
00395 if (cmd != FN_ZERO) {
00396 residual_size = get_ur_golomb_shorten(&s->gb, ENERGYSIZE);
00397
00398 if (s->version == 0)
00399 residual_size--;
00400 }
00401
00402 if (s->nmean == 0)
00403 coffset = s->offset[channel][0];
00404 else {
00405 int32_t sum = (s->version < 2) ? 0 : s->nmean / 2;
00406 for (i=0; i<s->nmean; i++)
00407 sum += s->offset[channel][i];
00408 coffset = sum / s->nmean;
00409 if (s->version >= 2)
00410 coffset >>= FFMIN(1, s->bitshift);
00411 }
00412 switch (cmd) {
00413 case FN_ZERO:
00414 for (i=0; i<s->blocksize; i++)
00415 s->decoded[channel][i] = 0;
00416 break;
00417 case FN_DIFF0:
00418 for (i=0; i<s->blocksize; i++)
00419 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + coffset;
00420 break;
00421 case FN_DIFF1:
00422 for (i=0; i<s->blocksize; i++)
00423 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + s->decoded[channel][i - 1];
00424 break;
00425 case FN_DIFF2:
00426 for (i=0; i<s->blocksize; i++)
00427 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 2*s->decoded[channel][i-1]
00428 - s->decoded[channel][i-2];
00429 break;
00430 case FN_DIFF3:
00431 for (i=0; i<s->blocksize; i++)
00432 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 3*s->decoded[channel][i-1]
00433 - 3*s->decoded[channel][i-2]
00434 + s->decoded[channel][i-3];
00435 break;
00436 case FN_QLPC:
00437 {
00438 int pred_order = get_ur_golomb_shorten(&s->gb, LPCQSIZE);
00439 if (pred_order > s->nwrap) {
00440 av_log(avctx, AV_LOG_ERROR,
00441 "invalid pred_order %d\n",
00442 pred_order);
00443 return -1;
00444 }
00445 for (i=0; i<pred_order; i++)
00446 s->decoded[channel][i - pred_order] -= coffset;
00447 decode_subframe_lpc(s, channel, residual_size, pred_order);
00448 if (coffset != 0)
00449 for (i=0; i < s->blocksize; i++)
00450 s->decoded[channel][i] += coffset;
00451 }
00452 }
00453 if (s->nmean > 0) {
00454 int32_t sum = (s->version < 2) ? 0 : s->blocksize / 2;
00455 for (i=0; i<s->blocksize; i++)
00456 sum += s->decoded[channel][i];
00457
00458 for (i=1; i<s->nmean; i++)
00459 s->offset[channel][i-1] = s->offset[channel][i];
00460
00461 if (s->version < 2)
00462 s->offset[channel][s->nmean - 1] = sum / s->blocksize;
00463 else
00464 s->offset[channel][s->nmean - 1] = (sum / s->blocksize) << s->bitshift;
00465 }
00466 for (i=-s->nwrap; i<0; i++)
00467 s->decoded[channel][i] = s->decoded[channel][i + s->blocksize];
00468
00469 fix_bitshift(s, s->decoded[channel]);
00470
00471 s->cur_chan++;
00472 if (s->cur_chan == s->channels) {
00473 samples = interleave_buffer(samples, s->channels, s->blocksize, s->decoded);
00474 s->cur_chan = 0;
00475 goto frame_done;
00476 }
00477 break;
00478 }
00479 break;
00480 case FN_VERBATIM:
00481 len = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
00482 while (len--) {
00483 get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
00484 }
00485 break;
00486 case FN_BITSHIFT:
00487 s->bitshift = get_ur_golomb_shorten(&s->gb, BITSHIFTSIZE);
00488 break;
00489 case FN_BLOCKSIZE:
00490 s->blocksize = get_uint(s, av_log2(s->blocksize));
00491 break;
00492 case FN_QUIT:
00493 *data_size = 0;
00494 return buf_size;
00495 break;
00496 default:
00497 av_log(avctx, AV_LOG_ERROR, "unknown shorten function %d\n", cmd);
00498 return -1;
00499 break;
00500 }
00501 }
00502 frame_done:
00503 *data_size = (int8_t *)samples - (int8_t *)data;
00504
00505
00506 s->bitindex = get_bits_count(&s->gb) - 8*((get_bits_count(&s->gb))/8);
00507 i= (get_bits_count(&s->gb))/8;
00508 if (i > buf_size) {
00509 av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
00510 s->bitstream_size=0;
00511 s->bitstream_index=0;
00512 return -1;
00513 }
00514 if (s->bitstream_size) {
00515 s->bitstream_index += i;
00516 s->bitstream_size -= i;
00517 return input_buf_size;
00518 } else
00519 return i;
00520 }
00521
00522 static av_cold int shorten_decode_close(AVCodecContext *avctx)
00523 {
00524 ShortenContext *s = avctx->priv_data;
00525 int i;
00526
00527 for (i = 0; i < s->channels; i++) {
00528 s->decoded[i] -= s->nwrap;
00529 av_freep(&s->decoded[i]);
00530 av_freep(&s->offset[i]);
00531 }
00532 av_freep(&s->bitstream);
00533 av_freep(&s->coeffs);
00534 return 0;
00535 }
00536
00537 static void shorten_flush(AVCodecContext *avctx){
00538 ShortenContext *s = avctx->priv_data;
00539
00540 s->bitstream_size=
00541 s->bitstream_index= 0;
00542 }
00543
00544 AVCodec ff_shorten_decoder = {
00545 "shorten",
00546 AVMEDIA_TYPE_AUDIO,
00547 CODEC_ID_SHORTEN,
00548 sizeof(ShortenContext),
00549 shorten_decode_init,
00550 NULL,
00551 shorten_decode_close,
00552 shorten_decode_frame,
00553 .flush= shorten_flush,
00554 .long_name= NULL_IF_CONFIG_SMALL("Shorten"),
00555 };