--- /dev/null
+/*
+ * ADPCM codecs
+ * Copyright (c) 2001-2003 The ffmpeg Project
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "avcodec.h"
+
+/**
+ * @file adpcm.c
+ * ADPCM codecs.
+ * First version by Francois Revol revol@free.fr
+ * Fringe ADPCM codecs (e.g., DK3 and DK4)
+ * by Mike Melanson (melanson@pcisys.net)
+ *
+ * Features and limitations:
+ *
+ * Reference documents:
+ * http://www.pcisys.net/~melanson/codecs/simpleaudio.html
+ * http://www.geocities.com/SiliconValley/8682/aud3.txt
+ * http://openquicktime.sourceforge.net/plugins.htm
+ * XAnim sources (xa_codec.c) http://www.rasnaimaging.com/people/lapus/download.html
+ * http://www.cs.ucla.edu/~leec/mediabench/applications.html
+ * SoX source code http://home.sprynet.com/~cbagwell/sox.html
+ */
+
+#define BLKSIZE 1024
+
+#define CLAMP_TO_SHORT(value) \
+if (value > 32767) \
+ value = 32767; \
+else if (value < -32768) \
+ value = -32768; \
+
+/* step_table[] and index_table[] are from the ADPCM reference source */
+/* This is the index table: */
+static const int index_table[16] = {
+ -1, -1, -1, -1, 2, 4, 6, 8,
+ -1, -1, -1, -1, 2, 4, 6, 8,
+};
+
+/**
+ * This is the step table. Note that many programs use slight deviations from
+ * this table, but such deviations are negligible:
+ */
+static const int step_table[89] = {
+ 7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
+ 19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
+ 50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
+ 130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
+ 337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
+ 876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
+ 2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
+ 5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
+ 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
+};
+
+/* Those are for MS-ADPCM */
+/* AdaptationTable[], AdaptCoeff1[], and AdaptCoeff2[] are from libsndfile */
+static const int AdaptationTable[] = {
+ 230, 230, 230, 230, 307, 409, 512, 614,
+ 768, 614, 512, 409, 307, 230, 230, 230
+};
+
+static const int AdaptCoeff1[] = {
+ 256, 512, 0, 192, 240, 460, 392
+};
+
+static const int AdaptCoeff2[] = {
+ 0, -256, 0, 64, 0, -208, -232
+};
+
+/* end of tables */
+
+typedef struct ADPCMChannelStatus {
+ int predictor;
+ short int step_index;
+ int step;
+ /* for encoding */
+ int prev_sample;
+
+ /* MS version */
+ short sample1;
+ short sample2;
+ int coeff1;
+ int coeff2;
+ int idelta;
+} ADPCMChannelStatus;
+
+typedef struct ADPCMContext {
+ int channel; /* for stereo MOVs, decode left, then decode right, then tell it's decoded */
+ ADPCMChannelStatus status[2];
+ short sample_buffer[32]; /* hold left samples while waiting for right samples */
+} ADPCMContext;
+
+/* XXX: implement encoding */
+
+static int adpcm_encode_init(AVCodecContext *avctx)
+{
+ if (avctx->channels > 2)
+ return -1; /* only stereo or mono =) */
+ switch(avctx->codec->id) {
+ case CODEC_ID_ADPCM_IMA_QT:
+ fprintf(stderr, "ADPCM: codec admcp_ima_qt unsupported for encoding !\n");
+ avctx->frame_size = 64; /* XXX: can multiple of avctx->channels * 64 (left and right blocks are interleaved) */
+ return -1;
+ break;
+ case CODEC_ID_ADPCM_IMA_WAV:
+ avctx->frame_size = (BLKSIZE - 4 * avctx->channels) * 8 / (4 * avctx->channels) + 1; /* each 16 bits sample gives one nibble */
+ /* and we have 4 bytes per channel overhead */
+ avctx->block_align = BLKSIZE;
+ /* seems frame_size isn't taken into account... have to buffer the samples :-( */
+ break;
+ case CODEC_ID_ADPCM_MS:
+ fprintf(stderr, "ADPCM: codec admcp_ms unsupported for encoding !\n");
+ return -1;
+ break;
+ default:
+ return -1;
+ break;
+ }
+
+ avctx->coded_frame= avcodec_alloc_frame();
+ avctx->coded_frame->key_frame= 1;
+
+ return 0;
+}
+
+static int adpcm_encode_close(AVCodecContext *avctx)
+{
+ av_freep(&avctx->coded_frame);
+
+ return 0;
+}
+
+
+static inline unsigned char adpcm_ima_compress_sample(ADPCMChannelStatus *c, short sample)
+{
+ int step_index;
+ unsigned char nibble;
+
+ int sign = 0; /* sign bit of the nibble (MSB) */
+ int delta, predicted_delta;
+
+ delta = sample - c->prev_sample;
+
+ if (delta < 0) {
+ sign = 1;
+ delta = -delta;
+ }
+
+ step_index = c->step_index;
+
+ /* nibble = 4 * delta / step_table[step_index]; */
+ nibble = (delta << 2) / step_table[step_index];
+
+ if (nibble > 7)
+ nibble = 7;
+
+ step_index += index_table[nibble];
+ if (step_index < 0)
+ step_index = 0;
+ if (step_index > 88)
+ step_index = 88;
+
+ /* what the decoder will find */
+ predicted_delta = ((step_table[step_index] * nibble) / 4) + (step_table[step_index] / 8);
+
+ if (sign)
+ c->prev_sample -= predicted_delta;
+ else
+ c->prev_sample += predicted_delta;
+
+ CLAMP_TO_SHORT(c->prev_sample);
+
+
+ nibble += sign << 3; /* sign * 8 */
+
+ /* save back */
+ c->step_index = step_index;
+
+ return nibble;
+}
+
+static int adpcm_encode_frame(AVCodecContext *avctx,
+ unsigned char *frame, int buf_size, void *data)
+{
+ int n;
+ short *samples;
+ unsigned char *dst;
+ ADPCMContext *c = avctx->priv_data;
+
+ dst = frame;
+ samples = (short *)data;
+/* n = (BLKSIZE - 4 * avctx->channels) / (2 * 8 * avctx->channels); */
+
+ switch(avctx->codec->id) {
+ case CODEC_ID_ADPCM_IMA_QT: /* XXX: can't test until we get .mov writer */
+ break;
+ case CODEC_ID_ADPCM_IMA_WAV:
+ n = avctx->frame_size / 8;
+ c->status[0].prev_sample = (signed short)samples[0]; /* XXX */
+/* c->status[0].step_index = 0; *//* XXX: not sure how to init the state machine */
+ *dst++ = (c->status[0].prev_sample) & 0xFF; /* little endian */
+ *dst++ = (c->status[0].prev_sample >> 8) & 0xFF;
+ *dst++ = (unsigned char)c->status[0].step_index;
+ *dst++ = 0; /* unknown */
+ samples++;
+ if (avctx->channels == 2) {
+ c->status[1].prev_sample = (signed short)samples[0];
+/* c->status[1].step_index = 0; */
+ *dst++ = (c->status[1].prev_sample) & 0xFF;
+ *dst++ = (c->status[1].prev_sample >> 8) & 0xFF;
+ *dst++ = (unsigned char)c->status[1].step_index;
+ *dst++ = 0;
+ samples++;
+ }
+
+ /* stereo: 4 bytes (8 samples) for left, 4 bytes for right, 4 bytes left, ... */
+ for (; n>0; n--) {
+ *dst = adpcm_ima_compress_sample(&c->status[0], samples[0]) & 0x0F;
+ *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels]) << 4) & 0xF0;
+ dst++;
+ *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 2]) & 0x0F;
+ *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 3]) << 4) & 0xF0;
+ dst++;
+ *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 4]) & 0x0F;
+ *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 5]) << 4) & 0xF0;
+ dst++;
+ *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 6]) & 0x0F;
+ *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 7]) << 4) & 0xF0;
+ dst++;
+ /* right channel */
+ if (avctx->channels == 2) {
+ *dst = adpcm_ima_compress_sample(&c->status[1], samples[1]);
+ *dst |= adpcm_ima_compress_sample(&c->status[1], samples[3]) << 4;
+ dst++;
+ *dst = adpcm_ima_compress_sample(&c->status[1], samples[5]);
+ *dst |= adpcm_ima_compress_sample(&c->status[1], samples[7]) << 4;
+ dst++;
+ *dst = adpcm_ima_compress_sample(&c->status[1], samples[9]);
+ *dst |= adpcm_ima_compress_sample(&c->status[1], samples[11]) << 4;
+ dst++;
+ *dst = adpcm_ima_compress_sample(&c->status[1], samples[13]);
+ *dst |= adpcm_ima_compress_sample(&c->status[1], samples[15]) << 4;
+ dst++;
+ }
+ samples += 8 * avctx->channels;
+ }
+ break;
+ default:
+ return -1;
+ }
+ return dst - frame;
+}
+
+static int adpcm_decode_init(AVCodecContext * avctx)
+{
+ ADPCMContext *c = avctx->priv_data;
+
+ c->channel = 0;
+ c->status[0].predictor = c->status[1].predictor = 0;
+ c->status[0].step_index = c->status[1].step_index = 0;
+ c->status[0].step = c->status[1].step = 0;
+
+ switch(avctx->codec->id) {
+ default:
+ break;
+ }
+ return 0;
+}
+
+static inline short adpcm_ima_expand_nibble(ADPCMChannelStatus *c, char nibble)
+{
+ int step_index;
+ int predictor;
+ int sign, delta, diff, step;
+
+ step = step_table[c->step_index];
+ step_index = c->step_index + index_table[(unsigned)nibble];
+ if (step_index < 0) step_index = 0;
+ else if (step_index > 88) step_index = 88;
+
+ sign = nibble & 8;
+ delta = nibble & 7;
+ /* perform direct multiplication instead of series of jumps proposed by
+ * the reference ADPCM implementation since modern CPUs can do the mults
+ * quickly enough */
+ diff = ((2 * delta + 1) * step) >> 3;
+ predictor = c->predictor;
+ if (sign) predictor -= diff;
+ else predictor += diff;
+
+ CLAMP_TO_SHORT(predictor);
+ c->predictor = predictor;
+ c->step_index = step_index;
+
+ return (short)predictor;
+}
+
+static inline short adpcm_4xa_expand_nibble(ADPCMChannelStatus *c, char nibble)
+{
+ int step_index;
+ int predictor;
+ int sign, delta, diff, step;
+
+ step = step_table[c->step_index];
+ step_index = c->step_index + index_table[(unsigned)nibble];
+ if (step_index < 0) step_index = 0;
+ else if (step_index > 88) step_index = 88;
+
+ sign = nibble & 8;
+ delta = nibble & 7;
+
+ diff = (delta*step + (step>>1))>>3; // difference to code above
+
+ predictor = c->predictor;
+ if (sign) predictor -= diff;
+ else predictor += diff;
+
+ CLAMP_TO_SHORT(predictor);
+ c->predictor = predictor;
+ c->step_index = step_index;
+
+ return (short)predictor;
+}
+
+static inline short adpcm_ms_expand_nibble(ADPCMChannelStatus *c, char nibble)
+{
+ int predictor;
+
+ predictor = (((c->sample1) * (c->coeff1)) + ((c->sample2) * (c->coeff2))) / 256;
+ predictor += (signed)((nibble & 0x08)?(nibble - 0x10):(nibble)) * c->idelta;
+ CLAMP_TO_SHORT(predictor);
+
+ c->sample2 = c->sample1;
+ c->sample1 = predictor;
+ c->idelta = (AdaptationTable[(int)nibble] * c->idelta) / 256;
+ if (c->idelta < 16) c->idelta = 16;
+
+ return (short)predictor;
+}
+
+/* DK3 ADPCM support macro */
+#define DK3_GET_NEXT_NIBBLE() \
+ if (decode_top_nibble_next) \
+ { \
+ nibble = (last_byte >> 4) & 0x0F; \
+ decode_top_nibble_next = 0; \
+ } \
+ else \
+ { \
+ last_byte = *src++; \
+ if (src >= buf + buf_size) break; \
+ nibble = last_byte & 0x0F; \
+ decode_top_nibble_next = 1; \
+ }
+
+static int adpcm_decode_frame(AVCodecContext *avctx,
+ void *data, int *data_size,
+ uint8_t *buf, int buf_size)
+{
+ ADPCMContext *c = avctx->priv_data;
+ ADPCMChannelStatus *cs;
+ int n, m, channel, i;
+ int block_predictor[2];
+ short *samples;
+ uint8_t *src;
+ int st; /* stereo */
+
+ /* DK3 ADPCM accounting variables */
+ unsigned char last_byte = 0;
+ unsigned char nibble;
+ int decode_top_nibble_next = 0;
+ int diff_channel;
+
+ samples = data;
+ src = buf;
+
+ st = avctx->channels == 2;
+
+ switch(avctx->codec->id) {
+ case CODEC_ID_ADPCM_IMA_QT:
+ n = (buf_size - 2);/* >> 2*avctx->channels;*/
+ channel = c->channel;
+ cs = &(c->status[channel]);
+ /* (pppppp) (piiiiiii) */
+
+ /* Bits 15-7 are the _top_ 9 bits of the 16-bit initial predictor value */
+ cs->predictor = (*src++) << 8;
+ cs->predictor |= (*src & 0x80);
+ cs->predictor &= 0xFF80;
+
+ /* sign extension */
+ if(cs->predictor & 0x8000)
+ cs->predictor -= 0x10000;
+
+ CLAMP_TO_SHORT(cs->predictor);
+
+ cs->step_index = (*src++) & 0x7F;
+
+ if (cs->step_index > 88) fprintf(stderr, "ERROR: step_index = %i\n", cs->step_index);
+ if (cs->step_index > 88) cs->step_index = 88;
+
+ cs->step = step_table[cs->step_index];
+
+ if (st && channel)
+ samples++;
+
+ *samples++ = cs->predictor;
+ samples += st;
+
+ for(m=32; n>0 && m>0; n--, m--) { /* in QuickTime, IMA is encoded by chuncks of 34 bytes (=64 samples) */
+ *samples = adpcm_ima_expand_nibble(cs, src[0] & 0x0F);
+ samples += avctx->channels;
+ *samples = adpcm_ima_expand_nibble(cs, (src[0] >> 4) & 0x0F);
+ samples += avctx->channels;
+ src ++;
+ }
+
+ if(st) { /* handle stereo interlacing */
+ c->channel = (channel + 1) % 2; /* we get one packet for left, then one for right data */
+ if(channel == 0) { /* wait for the other packet before outputing anything */
+ *data_size = 0;
+ return src - buf;
+ }
+ }
+ break;
+ case CODEC_ID_ADPCM_IMA_WAV:
+ if (buf_size > BLKSIZE) {
+ if (avctx->block_align != 0)
+ buf_size = avctx->block_align;
+ else
+ buf_size = BLKSIZE;
+ }
+ // XXX: do as per-channel loop
+ cs = &(c->status[0]);
+ cs->predictor = (*src++) & 0x0FF;
+ cs->predictor |= ((*src++) << 8) & 0x0FF00;
+ if(cs->predictor & 0x8000)
+ cs->predictor -= 0x10000;
+ CLAMP_TO_SHORT(cs->predictor);
+
+ // XXX: is this correct ??: *samples++ = cs->predictor;
+
+ cs->step_index = *src++;
+ if (cs->step_index < 0) cs->step_index = 0;
+ if (cs->step_index > 88) cs->step_index = 88;
+ if (*src++) fprintf(stderr, "unused byte should be null !!\n"); /* unused */
+
+ if (st) {
+ cs = &(c->status[1]);
+ cs->predictor = (*src++) & 0x0FF;
+ cs->predictor |= ((*src++) << 8) & 0x0FF00;
+ if(cs->predictor & 0x8000)
+ cs->predictor -= 0x10000;
+ CLAMP_TO_SHORT(cs->predictor);
+
+ // XXX: is this correct ??: *samples++ = cs->predictor;
+
+ cs->step_index = *src++;
+ if (cs->step_index < 0) cs->step_index = 0;
+ if (cs->step_index > 88) cs->step_index = 88;
+ src++; /* if != 0 -> out-of-sync */
+ }
+
+ for(m=4; src < (buf + buf_size);) {
+ *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[0] & 0x0F);
+ if (st)
+ *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[4] & 0x0F);
+ *samples++ = adpcm_ima_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
+ if (st) {
+ *samples++ = adpcm_ima_expand_nibble(&c->status[1], (src[4] >> 4) & 0x0F);
+ if (!--m) {
+ m=4;
+ src+=4;
+ }
+ }
+ src++;
+ }
+ break;
+ case CODEC_ID_ADPCM_4XM:
+ cs = &(c->status[0]);
+ c->status[0].predictor= (int16_t)(src[0] + (src[1]<<8)); src+=2;
+ if(st){
+ c->status[1].predictor= (int16_t)(src[0] + (src[1]<<8)); src+=2;
+ }
+ c->status[0].step_index= (int16_t)(src[0] + (src[1]<<8)); src+=2;
+ if(st){
+ c->status[1].step_index= (int16_t)(src[0] + (src[1]<<8)); src+=2;
+ }
+// if (cs->step_index < 0) cs->step_index = 0;
+// if (cs->step_index > 88) cs->step_index = 88;
+
+ m= (buf_size - (src - buf))>>st;
+//printf("%d %d %d %d\n", st, m, c->status[0].predictor, c->status[0].step_index);
+ //FIXME / XXX decode chanels individual & interleave samples
+ for(i=0; i<m; i++) {
+ *samples++ = adpcm_4xa_expand_nibble(&c->status[0], src[i] & 0x0F);
+ if (st)
+ *samples++ = adpcm_4xa_expand_nibble(&c->status[1], src[i+m] & 0x0F);
+ *samples++ = adpcm_4xa_expand_nibble(&c->status[0], src[i] >> 4);
+ if (st)
+ *samples++ = adpcm_4xa_expand_nibble(&c->status[1], src[i+m] >> 4);
+ }
+
+ src += m<<st;
+
+ break;
+ case CODEC_ID_ADPCM_MS:
+
+ if (buf_size > BLKSIZE) {
+ if (avctx->block_align != 0)
+ buf_size = avctx->block_align;
+ else
+ buf_size = BLKSIZE;
+ }
+ n = buf_size - 7 * avctx->channels;
+ if (n < 0)
+ return -1;
+ block_predictor[0] = (*src++); /* should be bound */
+ block_predictor[0] = (block_predictor[0] < 0)?(0):((block_predictor[0] > 7)?(7):(block_predictor[0]));
+ block_predictor[1] = 0;
+ if (st)
+ block_predictor[1] = (*src++);
+ block_predictor[1] = (block_predictor[1] < 0)?(0):((block_predictor[1] > 7)?(7):(block_predictor[1]));
+ c->status[0].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
+ if (c->status[0].idelta & 0x08000)
+ c->status[0].idelta -= 0x10000;
+ src+=2;
+ if (st)
+ c->status[1].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
+ if (st && c->status[1].idelta & 0x08000)
+ c->status[1].idelta |= 0xFFFF0000;
+ if (st)
+ src+=2;
+ c->status[0].coeff1 = AdaptCoeff1[block_predictor[0]];
+ c->status[0].coeff2 = AdaptCoeff2[block_predictor[0]];
+ c->status[1].coeff1 = AdaptCoeff1[block_predictor[1]];
+ c->status[1].coeff2 = AdaptCoeff2[block_predictor[1]];
+
+ c->status[0].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
+ src+=2;
+ if (st) c->status[1].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
+ if (st) src+=2;
+ c->status[0].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
+ src+=2;
+ if (st) c->status[1].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
+ if (st) src+=2;
+
+ *samples++ = c->status[0].sample1;
+ if (st) *samples++ = c->status[1].sample1;
+ *samples++ = c->status[0].sample2;
+ if (st) *samples++ = c->status[1].sample2;
+ for(;n>0;n--) {
+ *samples++ = adpcm_ms_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
+ *samples++ = adpcm_ms_expand_nibble(&c->status[st], src[0] & 0x0F);
+ src ++;
+ }
+ break;
+ case CODEC_ID_ADPCM_IMA_DK4:
+ if (buf_size > BLKSIZE) {
+ if (avctx->block_align != 0)
+ buf_size = avctx->block_align;
+ else
+ buf_size = BLKSIZE;
+ }
+ c->status[0].predictor = (src[0] | (src[1] << 8));
+ c->status[0].step_index = src[2];
+ src += 4;
+ if(c->status[0].predictor & 0x8000)
+ c->status[0].predictor -= 0x10000;
+ *samples++ = c->status[0].predictor;
+ if (st) {
+ c->status[1].predictor = (src[0] | (src[1] << 8));
+ c->status[1].step_index = src[2];
+ src += 4;
+ if(c->status[1].predictor & 0x8000)
+ c->status[1].predictor -= 0x10000;
+ *samples++ = c->status[1].predictor;
+ }
+ while (src < buf + buf_size) {
+
+ /* take care of the top nibble (always left or mono channel) */
+ *samples++ = adpcm_ima_expand_nibble(&c->status[0],
+ (src[0] >> 4) & 0x0F);
+
+ /* take care of the bottom nibble, which is right sample for
+ * stereo, or another mono sample */
+ if (st)
+ *samples++ = adpcm_ima_expand_nibble(&c->status[1],
+ src[0] & 0x0F);
+ else
+ *samples++ = adpcm_ima_expand_nibble(&c->status[0],
+ src[0] & 0x0F);
+
+ src++;
+ }
+ break;
+ case CODEC_ID_ADPCM_IMA_DK3:
+ if (buf_size > BLKSIZE) {
+ if (avctx->block_align != 0)
+ buf_size = avctx->block_align;
+ else
+ buf_size = BLKSIZE;
+ }
+ c->status[0].predictor = (src[10] | (src[11] << 8));
+ c->status[1].predictor = (src[12] | (src[13] << 8));
+ c->status[0].step_index = src[14];
+ c->status[1].step_index = src[15];
+ /* sign extend the predictors */
+ if(c->status[0].predictor & 0x8000)
+ c->status[0].predictor -= 0x10000;
+ if(c->status[1].predictor & 0x8000)
+ c->status[1].predictor -= 0x10000;
+ src += 16;
+ diff_channel = c->status[1].predictor;
+
+ /* the DK3_GET_NEXT_NIBBLE macro issues the break statement when
+ * the buffer is consumed */
+ while (1) {
+
+ /* for this algorithm, c->status[0] is the sum channel and
+ * c->status[1] is the diff channel */
+
+ /* process the first predictor of the sum channel */
+ DK3_GET_NEXT_NIBBLE();
+ adpcm_ima_expand_nibble(&c->status[0], nibble);
+
+ /* process the diff channel predictor */
+ DK3_GET_NEXT_NIBBLE();
+ adpcm_ima_expand_nibble(&c->status[1], nibble);
+
+ /* process the first pair of stereo PCM samples */
+ diff_channel = (diff_channel + c->status[1].predictor) / 2;
+ *samples++ = c->status[0].predictor + c->status[1].predictor;
+ *samples++ = c->status[0].predictor - c->status[1].predictor;
+
+ /* process the second predictor of the sum channel */
+ DK3_GET_NEXT_NIBBLE();
+ adpcm_ima_expand_nibble(&c->status[0], nibble);
+
+ /* process the second pair of stereo PCM samples */
+ diff_channel = (diff_channel + c->status[1].predictor) / 2;
+ *samples++ = c->status[0].predictor + c->status[1].predictor;
+ *samples++ = c->status[0].predictor - c->status[1].predictor;
+ }
+ break;
+ default:
+ *data_size = 0;
+ return -1;
+ }
+ *data_size = (uint8_t *)samples - (uint8_t *)data;
+ return src - buf;
+}
+
+#define ADPCM_CODEC(id, name) \
+AVCodec name ## _encoder = { \
+ #name, \
+ CODEC_TYPE_AUDIO, \
+ id, \
+ sizeof(ADPCMContext), \
+ adpcm_encode_init, \
+ adpcm_encode_frame, \
+ adpcm_encode_close, \
+ NULL, \
+}; \
+AVCodec name ## _decoder = { \
+ #name, \
+ CODEC_TYPE_AUDIO, \
+ id, \
+ sizeof(ADPCMContext), \
+ adpcm_decode_init, \
+ NULL, \
+ NULL, \
+ adpcm_decode_frame, \
+};
+
+ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);
+ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);
+ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK3, adpcm_ima_dk3);
+ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK4, adpcm_ima_dk4);
+ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);
+ADPCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);
+
+#undef ADPCM_CODEC
projects / synfig.git / blobdiff