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libavcodec/adpcmenc.c

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00001 /*
00002  * Copyright (c) 2001-2003 The ffmpeg Project
00003  *
00004  * This file is part of FFmpeg.
00005  *
00006  * FFmpeg is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * FFmpeg is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with FFmpeg; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 
00021 #include "avcodec.h"
00022 #include "get_bits.h"
00023 #include "put_bits.h"
00024 #include "bytestream.h"
00025 #include "adpcm.h"
00026 #include "adpcm_data.h"
00027 
00038 typedef struct TrellisPath {
00039     int nibble;
00040     int prev;
00041 } TrellisPath;
00042 
00043 typedef struct TrellisNode {
00044     uint32_t ssd;
00045     int path;
00046     int sample1;
00047     int sample2;
00048     int step;
00049 } TrellisNode;
00050 
00051 typedef struct ADPCMEncodeContext {
00052     ADPCMChannelStatus status[6];
00053     TrellisPath *paths;
00054     TrellisNode *node_buf;
00055     TrellisNode **nodep_buf;
00056     uint8_t *trellis_hash;
00057 } ADPCMEncodeContext;
00058 
00059 #define FREEZE_INTERVAL 128
00060 
00061 static av_cold int adpcm_encode_init(AVCodecContext *avctx)
00062 {
00063     ADPCMEncodeContext *s = avctx->priv_data;
00064     uint8_t *extradata;
00065     int i;
00066     if (avctx->channels > 2)
00067         return -1; /* only stereo or mono =) */
00068 
00069     if (avctx->trellis && (unsigned)avctx->trellis > 16U) {
00070         av_log(avctx, AV_LOG_ERROR, "invalid trellis size\n");
00071         return -1;
00072     }
00073 
00074     if (avctx->trellis) {
00075         int frontier  = 1 << avctx->trellis;
00076         int max_paths =  frontier * FREEZE_INTERVAL;
00077         FF_ALLOC_OR_GOTO(avctx, s->paths,
00078                          max_paths * sizeof(*s->paths), error);
00079         FF_ALLOC_OR_GOTO(avctx, s->node_buf,
00080                          2 * frontier * sizeof(*s->node_buf),  error);
00081         FF_ALLOC_OR_GOTO(avctx, s->nodep_buf,
00082                          2 * frontier * sizeof(*s->nodep_buf), error);
00083         FF_ALLOC_OR_GOTO(avctx, s->trellis_hash,
00084                          65536 * sizeof(*s->trellis_hash), error);
00085     }
00086 
00087     avctx->bits_per_coded_sample = av_get_bits_per_sample(avctx->codec->id);
00088 
00089     switch (avctx->codec->id) {
00090     case CODEC_ID_ADPCM_IMA_WAV:
00091         /* each 16 bits sample gives one nibble
00092            and we have 4 bytes per channel overhead */
00093         avctx->frame_size = (BLKSIZE - 4 * avctx->channels) * 8 /
00094                             (4 * avctx->channels) + 1;
00095         /* seems frame_size isn't taken into account...
00096            have to buffer the samples :-( */
00097         avctx->block_align = BLKSIZE;
00098         avctx->bits_per_coded_sample = 4;
00099         break;
00100     case CODEC_ID_ADPCM_IMA_QT:
00101         avctx->frame_size  = 64;
00102         avctx->block_align = 34 * avctx->channels;
00103         break;
00104     case CODEC_ID_ADPCM_MS:
00105         /* each 16 bits sample gives one nibble
00106            and we have 7 bytes per channel overhead */
00107         avctx->frame_size = (BLKSIZE - 7 * avctx->channels) * 2 / avctx->channels + 2;
00108         avctx->block_align = BLKSIZE;
00109         avctx->bits_per_coded_sample = 4;
00110         avctx->extradata_size = 32;
00111         extradata = avctx->extradata = av_malloc(avctx->extradata_size);
00112         if (!extradata)
00113             return AVERROR(ENOMEM);
00114         bytestream_put_le16(&extradata, avctx->frame_size);
00115         bytestream_put_le16(&extradata, 7); /* wNumCoef */
00116         for (i = 0; i < 7; i++) {
00117             bytestream_put_le16(&extradata, ff_adpcm_AdaptCoeff1[i] * 4);
00118             bytestream_put_le16(&extradata, ff_adpcm_AdaptCoeff2[i] * 4);
00119         }
00120         break;
00121     case CODEC_ID_ADPCM_YAMAHA:
00122         avctx->frame_size  = BLKSIZE * avctx->channels;
00123         avctx->block_align = BLKSIZE;
00124         break;
00125     case CODEC_ID_ADPCM_SWF:
00126         if (avctx->sample_rate != 11025 &&
00127             avctx->sample_rate != 22050 &&
00128             avctx->sample_rate != 44100) {
00129             av_log(avctx, AV_LOG_ERROR, "Sample rate must be 11025, "
00130                    "22050 or 44100\n");
00131             goto error;
00132         }
00133         avctx->frame_size = 512 * (avctx->sample_rate / 11025);
00134         break;
00135     default:
00136         goto error;
00137     }
00138 
00139     avctx->coded_frame = avcodec_alloc_frame();
00140     avctx->coded_frame->key_frame= 1;
00141 
00142     return 0;
00143 error:
00144     av_freep(&s->paths);
00145     av_freep(&s->node_buf);
00146     av_freep(&s->nodep_buf);
00147     av_freep(&s->trellis_hash);
00148     return -1;
00149 }
00150 
00151 static av_cold int adpcm_encode_close(AVCodecContext *avctx)
00152 {
00153     ADPCMEncodeContext *s = avctx->priv_data;
00154     av_freep(&avctx->coded_frame);
00155     av_freep(&s->paths);
00156     av_freep(&s->node_buf);
00157     av_freep(&s->nodep_buf);
00158     av_freep(&s->trellis_hash);
00159 
00160     return 0;
00161 }
00162 
00163 
00164 static inline unsigned char adpcm_ima_compress_sample(ADPCMChannelStatus *c,
00165                                                       short sample)
00166 {
00167     int delta  = sample - c->prev_sample;
00168     int nibble = FFMIN(7, abs(delta) * 4 /
00169                        ff_adpcm_step_table[c->step_index]) + (delta < 0) * 8;
00170     c->prev_sample += ((ff_adpcm_step_table[c->step_index] *
00171                         ff_adpcm_yamaha_difflookup[nibble]) / 8);
00172     c->prev_sample = av_clip_int16(c->prev_sample);
00173     c->step_index  = av_clip(c->step_index + ff_adpcm_index_table[nibble], 0, 88);
00174     return nibble;
00175 }
00176 
00177 static inline unsigned char adpcm_ima_qt_compress_sample(ADPCMChannelStatus *c,
00178                                                          short sample)
00179 {
00180     int delta  = sample - c->prev_sample;
00181     int diff, step = ff_adpcm_step_table[c->step_index];
00182     int nibble = 8*(delta < 0);
00183 
00184     delta= abs(delta);
00185     diff = delta + (step >> 3);
00186 
00187     if (delta >= step) {
00188         nibble |= 4;
00189         delta  -= step;
00190     }
00191     step >>= 1;
00192     if (delta >= step) {
00193         nibble |= 2;
00194         delta  -= step;
00195     }
00196     step >>= 1;
00197     if (delta >= step) {
00198         nibble |= 1;
00199         delta  -= step;
00200     }
00201     diff -= delta;
00202 
00203     if (nibble & 8)
00204         c->prev_sample -= diff;
00205     else
00206         c->prev_sample += diff;
00207 
00208     c->prev_sample = av_clip_int16(c->prev_sample);
00209     c->step_index  = av_clip(c->step_index + ff_adpcm_index_table[nibble], 0, 88);
00210 
00211     return nibble;
00212 }
00213 
00214 static inline unsigned char adpcm_ms_compress_sample(ADPCMChannelStatus *c,
00215                                                      short sample)
00216 {
00217     int predictor, nibble, bias;
00218 
00219     predictor = (((c->sample1) * (c->coeff1)) +
00220                 (( c->sample2) * (c->coeff2))) / 64;
00221 
00222     nibble = sample - predictor;
00223     if (nibble >= 0)
00224         bias =  c->idelta / 2;
00225     else
00226         bias = -c->idelta / 2;
00227 
00228     nibble = (nibble + bias) / c->idelta;
00229     nibble = av_clip(nibble, -8, 7) & 0x0F;
00230 
00231     predictor += (signed)((nibble & 0x08) ? (nibble - 0x10) : nibble) * c->idelta;
00232 
00233     c->sample2 = c->sample1;
00234     c->sample1 = av_clip_int16(predictor);
00235 
00236     c->idelta = (ff_adpcm_AdaptationTable[(int)nibble] * c->idelta) >> 8;
00237     if (c->idelta < 16)
00238         c->idelta = 16;
00239 
00240     return nibble;
00241 }
00242 
00243 static inline unsigned char adpcm_yamaha_compress_sample(ADPCMChannelStatus *c,
00244                                                          short sample)
00245 {
00246     int nibble, delta;
00247 
00248     if (!c->step) {
00249         c->predictor = 0;
00250         c->step      = 127;
00251     }
00252 
00253     delta = sample - c->predictor;
00254 
00255     nibble = FFMIN(7, abs(delta) * 4 / c->step) + (delta < 0) * 8;
00256 
00257     c->predictor += ((c->step * ff_adpcm_yamaha_difflookup[nibble]) / 8);
00258     c->predictor = av_clip_int16(c->predictor);
00259     c->step = (c->step * ff_adpcm_yamaha_indexscale[nibble]) >> 8;
00260     c->step = av_clip(c->step, 127, 24567);
00261 
00262     return nibble;
00263 }
00264 
00265 static void adpcm_compress_trellis(AVCodecContext *avctx, const short *samples,
00266                                    uint8_t *dst, ADPCMChannelStatus *c, int n)
00267 {
00268     //FIXME 6% faster if frontier is a compile-time constant
00269     ADPCMEncodeContext *s = avctx->priv_data;
00270     const int frontier = 1 << avctx->trellis;
00271     const int stride   = avctx->channels;
00272     const int version  = avctx->codec->id;
00273     TrellisPath *paths       = s->paths, *p;
00274     TrellisNode *node_buf    = s->node_buf;
00275     TrellisNode **nodep_buf  = s->nodep_buf;
00276     TrellisNode **nodes      = nodep_buf; // nodes[] is always sorted by .ssd
00277     TrellisNode **nodes_next = nodep_buf + frontier;
00278     int pathn = 0, froze = -1, i, j, k, generation = 0;
00279     uint8_t *hash = s->trellis_hash;
00280     memset(hash, 0xff, 65536 * sizeof(*hash));
00281 
00282     memset(nodep_buf, 0, 2 * frontier * sizeof(*nodep_buf));
00283     nodes[0]          = node_buf + frontier;
00284     nodes[0]->ssd     = 0;
00285     nodes[0]->path    = 0;
00286     nodes[0]->step    = c->step_index;
00287     nodes[0]->sample1 = c->sample1;
00288     nodes[0]->sample2 = c->sample2;
00289     if (version == CODEC_ID_ADPCM_IMA_WAV ||
00290         version == CODEC_ID_ADPCM_IMA_QT  ||
00291         version == CODEC_ID_ADPCM_SWF)
00292         nodes[0]->sample1 = c->prev_sample;
00293     if (version == CODEC_ID_ADPCM_MS)
00294         nodes[0]->step = c->idelta;
00295     if (version == CODEC_ID_ADPCM_YAMAHA) {
00296         if (c->step == 0) {
00297             nodes[0]->step    = 127;
00298             nodes[0]->sample1 = 0;
00299         } else {
00300             nodes[0]->step    = c->step;
00301             nodes[0]->sample1 = c->predictor;
00302         }
00303     }
00304 
00305     for (i = 0; i < n; i++) {
00306         TrellisNode *t = node_buf + frontier*(i&1);
00307         TrellisNode **u;
00308         int sample   = samples[i * stride];
00309         int heap_pos = 0;
00310         memset(nodes_next, 0, frontier * sizeof(TrellisNode*));
00311         for (j = 0; j < frontier && nodes[j]; j++) {
00312             // higher j have higher ssd already, so they're likely
00313             // to yield a suboptimal next sample too
00314             const int range = (j < frontier / 2) ? 1 : 0;
00315             const int step  = nodes[j]->step;
00316             int nidx;
00317             if (version == CODEC_ID_ADPCM_MS) {
00318                 const int predictor = ((nodes[j]->sample1 * c->coeff1) +
00319                                        (nodes[j]->sample2 * c->coeff2)) / 64;
00320                 const int div  = (sample - predictor) / step;
00321                 const int nmin = av_clip(div-range, -8, 6);
00322                 const int nmax = av_clip(div+range, -7, 7);
00323                 for (nidx = nmin; nidx <= nmax; nidx++) {
00324                     const int nibble = nidx & 0xf;
00325                     int dec_sample   = predictor + nidx * step;
00326 #define STORE_NODE(NAME, STEP_INDEX)\
00327                     int d;\
00328                     uint32_t ssd;\
00329                     int pos;\
00330                     TrellisNode *u;\
00331                     uint8_t *h;\
00332                     dec_sample = av_clip_int16(dec_sample);\
00333                     d = sample - dec_sample;\
00334                     ssd = nodes[j]->ssd + d*d;\
00335                     /* Check for wraparound, skip such samples completely. \
00336                      * Note, changing ssd to a 64 bit variable would be \
00337                      * simpler, avoiding this check, but it's slower on \
00338                      * x86 32 bit at the moment. */\
00339                     if (ssd < nodes[j]->ssd)\
00340                         goto next_##NAME;\
00341                     /* Collapse any two states with the same previous sample value. \
00342                      * One could also distinguish states by step and by 2nd to last
00343                      * sample, but the effects of that are negligible.
00344                      * Since nodes in the previous generation are iterated
00345                      * through a heap, they're roughly ordered from better to
00346                      * worse, but not strictly ordered. Therefore, an earlier
00347                      * node with the same sample value is better in most cases
00348                      * (and thus the current is skipped), but not strictly
00349                      * in all cases. Only skipping samples where ssd >=
00350                      * ssd of the earlier node with the same sample gives
00351                      * slightly worse quality, though, for some reason. */ \
00352                     h = &hash[(uint16_t) dec_sample];\
00353                     if (*h == generation)\
00354                         goto next_##NAME;\
00355                     if (heap_pos < frontier) {\
00356                         pos = heap_pos++;\
00357                     } else {\
00358                         /* Try to replace one of the leaf nodes with the new \
00359                          * one, but try a different slot each time. */\
00360                         pos = (frontier >> 1) +\
00361                               (heap_pos & ((frontier >> 1) - 1));\
00362                         if (ssd > nodes_next[pos]->ssd)\
00363                             goto next_##NAME;\
00364                         heap_pos++;\
00365                     }\
00366                     *h = generation;\
00367                     u  = nodes_next[pos];\
00368                     if (!u) {\
00369                         assert(pathn < FREEZE_INTERVAL << avctx->trellis);\
00370                         u = t++;\
00371                         nodes_next[pos] = u;\
00372                         u->path = pathn++;\
00373                     }\
00374                     u->ssd  = ssd;\
00375                     u->step = STEP_INDEX;\
00376                     u->sample2 = nodes[j]->sample1;\
00377                     u->sample1 = dec_sample;\
00378                     paths[u->path].nibble = nibble;\
00379                     paths[u->path].prev   = nodes[j]->path;\
00380                     /* Sift the newly inserted node up in the heap to \
00381                      * restore the heap property. */\
00382                     while (pos > 0) {\
00383                         int parent = (pos - 1) >> 1;\
00384                         if (nodes_next[parent]->ssd <= ssd)\
00385                             break;\
00386                         FFSWAP(TrellisNode*, nodes_next[parent], nodes_next[pos]);\
00387                         pos = parent;\
00388                     }\
00389                     next_##NAME:;
00390                     STORE_NODE(ms, FFMAX(16,
00391                                (ff_adpcm_AdaptationTable[nibble] * step) >> 8));
00392                 }
00393             } else if (version == CODEC_ID_ADPCM_IMA_WAV ||
00394                        version == CODEC_ID_ADPCM_IMA_QT  ||
00395                        version == CODEC_ID_ADPCM_SWF) {
00396 #define LOOP_NODES(NAME, STEP_TABLE, STEP_INDEX)\
00397                 const int predictor = nodes[j]->sample1;\
00398                 const int div = (sample - predictor) * 4 / STEP_TABLE;\
00399                 int nmin = av_clip(div - range, -7, 6);\
00400                 int nmax = av_clip(div + range, -6, 7);\
00401                 if (nmin <= 0)\
00402                     nmin--; /* distinguish -0 from +0 */\
00403                 if (nmax < 0)\
00404                     nmax--;\
00405                 for (nidx = nmin; nidx <= nmax; nidx++) {\
00406                     const int nibble = nidx < 0 ? 7 - nidx : nidx;\
00407                     int dec_sample = predictor +\
00408                                     (STEP_TABLE *\
00409                                      ff_adpcm_yamaha_difflookup[nibble]) / 8;\
00410                     STORE_NODE(NAME, STEP_INDEX);\
00411                 }
00412                 LOOP_NODES(ima, ff_adpcm_step_table[step],
00413                            av_clip(step + ff_adpcm_index_table[nibble], 0, 88));
00414             } else { //CODEC_ID_ADPCM_YAMAHA
00415                 LOOP_NODES(yamaha, step,
00416                            av_clip((step * ff_adpcm_yamaha_indexscale[nibble]) >> 8,
00417                                    127, 24567));
00418 #undef LOOP_NODES
00419 #undef STORE_NODE
00420             }
00421         }
00422 
00423         u = nodes;
00424         nodes = nodes_next;
00425         nodes_next = u;
00426 
00427         generation++;
00428         if (generation == 255) {
00429             memset(hash, 0xff, 65536 * sizeof(*hash));
00430             generation = 0;
00431         }
00432 
00433         // prevent overflow
00434         if (nodes[0]->ssd > (1 << 28)) {
00435             for (j = 1; j < frontier && nodes[j]; j++)
00436                 nodes[j]->ssd -= nodes[0]->ssd;
00437             nodes[0]->ssd = 0;
00438         }
00439 
00440         // merge old paths to save memory
00441         if (i == froze + FREEZE_INTERVAL) {
00442             p = &paths[nodes[0]->path];
00443             for (k = i; k > froze; k--) {
00444                 dst[k] = p->nibble;
00445                 p = &paths[p->prev];
00446             }
00447             froze = i;
00448             pathn = 0;
00449             // other nodes might use paths that don't coincide with the frozen one.
00450             // checking which nodes do so is too slow, so just kill them all.
00451             // this also slightly improves quality, but I don't know why.
00452             memset(nodes + 1, 0, (frontier - 1) * sizeof(TrellisNode*));
00453         }
00454     }
00455 
00456     p = &paths[nodes[0]->path];
00457     for (i = n - 1; i > froze; i--) {
00458         dst[i] = p->nibble;
00459         p = &paths[p->prev];
00460     }
00461 
00462     c->predictor  = nodes[0]->sample1;
00463     c->sample1    = nodes[0]->sample1;
00464     c->sample2    = nodes[0]->sample2;
00465     c->step_index = nodes[0]->step;
00466     c->step       = nodes[0]->step;
00467     c->idelta     = nodes[0]->step;
00468 }
00469 
00470 static int adpcm_encode_frame(AVCodecContext *avctx,
00471                               unsigned char *frame, int buf_size, void *data)
00472 {
00473     int n, i, st;
00474     short *samples;
00475     unsigned char *dst;
00476     ADPCMEncodeContext *c = avctx->priv_data;
00477     uint8_t *buf;
00478 
00479     dst = frame;
00480     samples = (short *)data;
00481     st = avctx->channels == 2;
00482     /* n = (BLKSIZE - 4 * avctx->channels) / (2 * 8 * avctx->channels); */
00483 
00484     switch(avctx->codec->id) {
00485     case CODEC_ID_ADPCM_IMA_WAV:
00486         n = avctx->frame_size / 8;
00487         c->status[0].prev_sample = (signed short)samples[0]; /* XXX */
00488         /* c->status[0].step_index = 0;
00489         XXX: not sure how to init the state machine */
00490         bytestream_put_le16(&dst, c->status[0].prev_sample);
00491         *dst++ = (unsigned char)c->status[0].step_index;
00492         *dst++ = 0; /* unknown */
00493         samples++;
00494         if (avctx->channels == 2) {
00495             c->status[1].prev_sample = (signed short)samples[0];
00496             /* c->status[1].step_index = 0; */
00497             bytestream_put_le16(&dst, c->status[1].prev_sample);
00498             *dst++ = (unsigned char)c->status[1].step_index;
00499             *dst++ = 0;
00500             samples++;
00501         }
00502 
00503         /* stereo: 4 bytes (8 samples) for left,
00504             4 bytes for right, 4 bytes left, ... */
00505         if (avctx->trellis > 0) {
00506             FF_ALLOC_OR_GOTO(avctx, buf, 2 * n * 8, error);
00507             adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n * 8);
00508             if (avctx->channels == 2)
00509                 adpcm_compress_trellis(avctx, samples + 1, buf + n * 8,
00510                                        &c->status[1], n * 8);
00511             for (i = 0; i < n; i++) {
00512                 *dst++ = buf[8 * i + 0] | (buf[8 * i + 1] << 4);
00513                 *dst++ = buf[8 * i + 2] | (buf[8 * i + 3] << 4);
00514                 *dst++ = buf[8 * i + 4] | (buf[8 * i + 5] << 4);
00515                 *dst++ = buf[8 * i + 6] | (buf[8 * i + 7] << 4);
00516                 if (avctx->channels == 2) {
00517                     uint8_t *buf1 = buf + n * 8;
00518                     *dst++ = buf1[8 * i + 0] | (buf1[8 * i + 1] << 4);
00519                     *dst++ = buf1[8 * i + 2] | (buf1[8 * i + 3] << 4);
00520                     *dst++ = buf1[8 * i + 4] | (buf1[8 * i + 5] << 4);
00521                     *dst++ = buf1[8 * i + 6] | (buf1[8 * i + 7] << 4);
00522                 }
00523             }
00524             av_free(buf);
00525         } else {
00526             for (; n > 0; n--) {
00527                 *dst    = adpcm_ima_compress_sample(&c->status[0], samples[0]);
00528                 *dst++ |= adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels    ]) << 4;
00529                 *dst    = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 2]);
00530                 *dst++ |= adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 3]) << 4;
00531                 *dst    = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 4]);
00532                 *dst++ |= adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 5]) << 4;
00533                 *dst    = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 6]);
00534                 *dst++ |= adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 7]) << 4;
00535                 /* right channel */
00536                 if (avctx->channels == 2) {
00537                     *dst    = adpcm_ima_compress_sample(&c->status[1], samples[1 ]);
00538                     *dst++ |= adpcm_ima_compress_sample(&c->status[1], samples[3 ]) << 4;
00539                     *dst    = adpcm_ima_compress_sample(&c->status[1], samples[5 ]);
00540                     *dst++ |= adpcm_ima_compress_sample(&c->status[1], samples[7 ]) << 4;
00541                     *dst    = adpcm_ima_compress_sample(&c->status[1], samples[9 ]);
00542                     *dst++ |= adpcm_ima_compress_sample(&c->status[1], samples[11]) << 4;
00543                     *dst    = adpcm_ima_compress_sample(&c->status[1], samples[13]);
00544                     *dst++ |= adpcm_ima_compress_sample(&c->status[1], samples[15]) << 4;
00545                 }
00546                 samples += 8 * avctx->channels;
00547             }
00548         }
00549         break;
00550     case CODEC_ID_ADPCM_IMA_QT:
00551     {
00552         int ch, i;
00553         PutBitContext pb;
00554         init_put_bits(&pb, dst, buf_size * 8);
00555 
00556         for (ch = 0; ch < avctx->channels; ch++) {
00557             put_bits(&pb, 9, (c->status[ch].prev_sample + 0x10000) >> 7);
00558             put_bits(&pb, 7,  c->status[ch].step_index);
00559             if (avctx->trellis > 0) {
00560                 uint8_t buf[64];
00561                 adpcm_compress_trellis(avctx, samples+ch, buf, &c->status[ch], 64);
00562                 for (i = 0; i < 64; i++)
00563                     put_bits(&pb, 4, buf[i ^ 1]);
00564             } else {
00565                 for (i = 0; i < 64; i += 2) {
00566                     int t1, t2;
00567                     t1 = adpcm_ima_qt_compress_sample(&c->status[ch],
00568                                                       samples[avctx->channels * (i + 0) + ch]);
00569                     t2 = adpcm_ima_qt_compress_sample(&c->status[ch],
00570                                                       samples[avctx->channels * (i + 1) + ch]);
00571                     put_bits(&pb, 4, t2);
00572                     put_bits(&pb, 4, t1);
00573                 }
00574             }
00575         }
00576 
00577         flush_put_bits(&pb);
00578         dst += put_bits_count(&pb) >> 3;
00579         break;
00580     }
00581     case CODEC_ID_ADPCM_SWF:
00582     {
00583         int i;
00584         PutBitContext pb;
00585         init_put_bits(&pb, dst, buf_size * 8);
00586 
00587         n = avctx->frame_size - 1;
00588 
00589         // store AdpcmCodeSize
00590         put_bits(&pb, 2, 2);    // set 4-bit flash adpcm format
00591 
00592         // init the encoder state
00593         for (i = 0; i < avctx->channels; i++) {
00594             // clip step so it fits 6 bits
00595             c->status[i].step_index = av_clip(c->status[i].step_index, 0, 63);
00596             put_sbits(&pb, 16, samples[i]);
00597             put_bits(&pb, 6, c->status[i].step_index);
00598             c->status[i].prev_sample = (signed short)samples[i];
00599         }
00600 
00601         if (avctx->trellis > 0) {
00602             FF_ALLOC_OR_GOTO(avctx, buf, 2 * n, error);
00603             adpcm_compress_trellis(avctx, samples + 2, buf, &c->status[0], n);
00604             if (avctx->channels == 2)
00605                 adpcm_compress_trellis(avctx, samples + 3, buf + n,
00606                                        &c->status[1], n);
00607             for (i = 0; i < n; i++) {
00608                 put_bits(&pb, 4, buf[i]);
00609                 if (avctx->channels == 2)
00610                     put_bits(&pb, 4, buf[n + i]);
00611             }
00612             av_free(buf);
00613         } else {
00614             for (i = 1; i < avctx->frame_size; i++) {
00615                 put_bits(&pb, 4, adpcm_ima_compress_sample(&c->status[0],
00616                          samples[avctx->channels * i]));
00617                 if (avctx->channels == 2)
00618                     put_bits(&pb, 4, adpcm_ima_compress_sample(&c->status[1],
00619                              samples[2 * i + 1]));
00620             }
00621         }
00622         flush_put_bits(&pb);
00623         dst += put_bits_count(&pb) >> 3;
00624         break;
00625     }
00626     case CODEC_ID_ADPCM_MS:
00627         for (i = 0; i < avctx->channels; i++) {
00628             int predictor = 0;
00629             *dst++ = predictor;
00630             c->status[i].coeff1 = ff_adpcm_AdaptCoeff1[predictor];
00631             c->status[i].coeff2 = ff_adpcm_AdaptCoeff2[predictor];
00632         }
00633         for (i = 0; i < avctx->channels; i++) {
00634             if (c->status[i].idelta < 16)
00635                 c->status[i].idelta = 16;
00636             bytestream_put_le16(&dst, c->status[i].idelta);
00637         }
00638         for (i = 0; i < avctx->channels; i++)
00639             c->status[i].sample2= *samples++;
00640         for (i = 0; i < avctx->channels; i++) {
00641             c->status[i].sample1 = *samples++;
00642             bytestream_put_le16(&dst, c->status[i].sample1);
00643         }
00644         for (i = 0; i < avctx->channels; i++)
00645             bytestream_put_le16(&dst, c->status[i].sample2);
00646 
00647         if (avctx->trellis > 0) {
00648             int n = avctx->block_align - 7 * avctx->channels;
00649             FF_ALLOC_OR_GOTO(avctx, buf, 2 * n, error);
00650             if (avctx->channels == 1) {
00651                 adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n);
00652                 for (i = 0; i < n; i += 2)
00653                     *dst++ = (buf[i] << 4) | buf[i + 1];
00654             } else {
00655                 adpcm_compress_trellis(avctx, samples,     buf,     &c->status[0], n);
00656                 adpcm_compress_trellis(avctx, samples + 1, buf + n, &c->status[1], n);
00657                 for (i = 0; i < n; i++)
00658                     *dst++ = (buf[i] << 4) | buf[n + i];
00659             }
00660             av_free(buf);
00661         } else {
00662             for (i = 7 * avctx->channels; i < avctx->block_align; i++) {
00663                 int nibble;
00664                 nibble  = adpcm_ms_compress_sample(&c->status[ 0], *samples++) << 4;
00665                 nibble |= adpcm_ms_compress_sample(&c->status[st], *samples++);
00666                 *dst++  = nibble;
00667             }
00668         }
00669         break;
00670     case CODEC_ID_ADPCM_YAMAHA:
00671         n = avctx->frame_size / 2;
00672         if (avctx->trellis > 0) {
00673             FF_ALLOC_OR_GOTO(avctx, buf, 2 * n * 2, error);
00674             n *= 2;
00675             if (avctx->channels == 1) {
00676                 adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n);
00677                 for (i = 0; i < n; i += 2)
00678                     *dst++ = buf[i] | (buf[i + 1] << 4);
00679             } else {
00680                 adpcm_compress_trellis(avctx, samples,     buf,     &c->status[0], n);
00681                 adpcm_compress_trellis(avctx, samples + 1, buf + n, &c->status[1], n);
00682                 for (i = 0; i < n; i++)
00683                     *dst++ = buf[i] | (buf[n + i] << 4);
00684             }
00685             av_free(buf);
00686         } else
00687             for (n *= avctx->channels; n > 0; n--) {
00688                 int nibble;
00689                 nibble  = adpcm_yamaha_compress_sample(&c->status[ 0], *samples++);
00690                 nibble |= adpcm_yamaha_compress_sample(&c->status[st], *samples++) << 4;
00691                 *dst++  = nibble;
00692             }
00693         break;
00694     default:
00695     error:
00696         return -1;
00697     }
00698     return dst - frame;
00699 }
00700 
00701 
00702 #define ADPCM_ENCODER(id_, name_, long_name_)               \
00703 AVCodec ff_ ## name_ ## _encoder = {                        \
00704     .name           = #name_,                               \
00705     .type           = AVMEDIA_TYPE_AUDIO,                   \
00706     .id             = id_,                                  \
00707     .priv_data_size = sizeof(ADPCMEncodeContext),           \
00708     .init           = adpcm_encode_init,                    \
00709     .encode         = adpcm_encode_frame,                   \
00710     .close          = adpcm_encode_close,                   \
00711     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16,   \
00712                                                       AV_SAMPLE_FMT_NONE}, \
00713     .long_name      = NULL_IF_CONFIG_SMALL(long_name_),     \
00714 }
00715 
00716 ADPCM_ENCODER(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt,   "ADPCM IMA QuickTime");
00717 ADPCM_ENCODER(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav, "ADPCM IMA WAV");
00718 ADPCM_ENCODER(CODEC_ID_ADPCM_MS, adpcm_ms,           "ADPCM Microsoft");
00719 ADPCM_ENCODER(CODEC_ID_ADPCM_SWF, adpcm_swf,         "ADPCM Shockwave Flash");
00720 ADPCM_ENCODER(CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha,   "ADPCM Yamaha");
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