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00031 #include "avcodec.h"
00032 #include "internal.h"
00033
00035 typedef struct EightSvxContext {
00036 AVFrame frame;
00037 uint8_t fib_acc[2];
00038 const int8_t *table;
00039
00040
00041
00042 uint8_t *data[2];
00043 int data_size;
00044 int data_idx;
00045 } EightSvxContext;
00046
00047 static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1,
00048 0, 1, 2, 3, 5, 8, 13, 21 };
00049 static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1,
00050 0, 1, 2, 4, 8, 16, 32, 64 };
00051
00052 #define MAX_FRAME_SIZE 32768
00053
00060 static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
00061 uint8_t *state, const int8_t *table, int channels)
00062 {
00063 uint8_t val = *state;
00064
00065 while (src_size--) {
00066 uint8_t d = *src++;
00067 val = av_clip_uint8(val + table[d & 0xF]);
00068 *dst = val;
00069 dst += channels;
00070 val = av_clip_uint8(val + table[d >> 4]);
00071 *dst = val;
00072 dst += channels;
00073 }
00074
00075 *state = val;
00076 }
00077
00078 static void raw_decode(uint8_t *dst, const int8_t *src, int src_size,
00079 int channels)
00080 {
00081 while (src_size--) {
00082 *dst = *src++ + 128;
00083 dst += channels;
00084 }
00085 }
00086
00088 static int eightsvx_decode_frame(AVCodecContext *avctx, void *data,
00089 int *got_frame_ptr, AVPacket *avpkt)
00090 {
00091 EightSvxContext *esc = avctx->priv_data;
00092 int buf_size;
00093 uint8_t *out_data;
00094 int ret;
00095 int is_compr = (avctx->codec_id != CODEC_ID_PCM_S8_PLANAR);
00096
00097
00098 if (avpkt->data) {
00099 int hdr_size = is_compr ? 2 : 0;
00100 int chan_size = (avpkt->size - hdr_size * avctx->channels) / avctx->channels;
00101
00102 if (avpkt->size < hdr_size * avctx->channels) {
00103 av_log(avctx, AV_LOG_ERROR, "packet size is too small\n");
00104 return AVERROR(EINVAL);
00105 }
00106 if (esc->data[0]) {
00107 av_log(avctx, AV_LOG_ERROR, "unexpected data after first packet\n");
00108 return AVERROR(EINVAL);
00109 }
00110
00111 if (is_compr) {
00112 esc->fib_acc[0] = avpkt->data[1] + 128;
00113 if (avctx->channels == 2)
00114 esc->fib_acc[1] = avpkt->data[2+chan_size+1] + 128;
00115 }
00116
00117 esc->data_idx = 0;
00118 esc->data_size = chan_size;
00119 if (!(esc->data[0] = av_malloc(chan_size)))
00120 return AVERROR(ENOMEM);
00121 if (avctx->channels == 2) {
00122 if (!(esc->data[1] = av_malloc(chan_size))) {
00123 av_freep(&esc->data[0]);
00124 return AVERROR(ENOMEM);
00125 }
00126 }
00127 memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size);
00128 if (avctx->channels == 2)
00129 memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size);
00130 }
00131 if (!esc->data[0]) {
00132 av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n");
00133 return AVERROR(EINVAL);
00134 }
00135
00136
00137 buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx);
00138 if (buf_size <= 0) {
00139 *got_frame_ptr = 0;
00140 return avpkt->size;
00141 }
00142
00143
00144 esc->frame.nb_samples = buf_size * (is_compr + 1);
00145 if ((ret = ff_get_buffer(avctx, &esc->frame)) < 0) {
00146 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00147 return ret;
00148 }
00149 out_data = esc->frame.data[0];
00150
00151 if (is_compr) {
00152 delta_decode(out_data, &esc->data[0][esc->data_idx], buf_size,
00153 &esc->fib_acc[0], esc->table, avctx->channels);
00154 if (avctx->channels == 2) {
00155 delta_decode(&out_data[1], &esc->data[1][esc->data_idx], buf_size,
00156 &esc->fib_acc[1], esc->table, avctx->channels);
00157 }
00158 } else {
00159 int ch;
00160 for (ch = 0; ch < avctx->channels; ch++) {
00161 raw_decode((int8_t *)&out_data[ch], &esc->data[ch][esc->data_idx],
00162 buf_size, avctx->channels);
00163 }
00164 }
00165 esc->data_idx += buf_size;
00166
00167 *got_frame_ptr = 1;
00168 *(AVFrame *)data = esc->frame;
00169
00170 return avpkt->size;
00171 }
00172
00174 static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
00175 {
00176 EightSvxContext *esc = avctx->priv_data;
00177
00178 if (avctx->channels < 1 || avctx->channels > 2) {
00179 av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n");
00180 return AVERROR(EINVAL);
00181 }
00182
00183 switch(avctx->codec->id) {
00184 case CODEC_ID_8SVX_FIB:
00185 esc->table = fibonacci;
00186 break;
00187 case CODEC_ID_8SVX_EXP:
00188 esc->table = exponential;
00189 break;
00190 case CODEC_ID_PCM_S8_PLANAR:
00191 break;
00192 default:
00193 return -1;
00194 }
00195 avctx->sample_fmt = AV_SAMPLE_FMT_U8;
00196
00197 avcodec_get_frame_defaults(&esc->frame);
00198 avctx->coded_frame = &esc->frame;
00199
00200 return 0;
00201 }
00202
00203 static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
00204 {
00205 EightSvxContext *esc = avctx->priv_data;
00206
00207 av_freep(&esc->data[0]);
00208 av_freep(&esc->data[1]);
00209
00210 return 0;
00211 }
00212
00213 AVCodec ff_eightsvx_fib_decoder = {
00214 .name = "8svx_fib",
00215 .type = AVMEDIA_TYPE_AUDIO,
00216 .id = CODEC_ID_8SVX_FIB,
00217 .priv_data_size = sizeof (EightSvxContext),
00218 .init = eightsvx_decode_init,
00219 .close = eightsvx_decode_close,
00220 .decode = eightsvx_decode_frame,
00221 .capabilities = CODEC_CAP_DELAY | CODEC_CAP_DR1,
00222 .long_name = NULL_IF_CONFIG_SMALL("8SVX fibonacci"),
00223 };
00224
00225 AVCodec ff_eightsvx_exp_decoder = {
00226 .name = "8svx_exp",
00227 .type = AVMEDIA_TYPE_AUDIO,
00228 .id = CODEC_ID_8SVX_EXP,
00229 .priv_data_size = sizeof (EightSvxContext),
00230 .init = eightsvx_decode_init,
00231 .close = eightsvx_decode_close,
00232 .decode = eightsvx_decode_frame,
00233 .capabilities = CODEC_CAP_DELAY | CODEC_CAP_DR1,
00234 .long_name = NULL_IF_CONFIG_SMALL("8SVX exponential"),
00235 };
00236
00237 AVCodec ff_pcm_s8_planar_decoder = {
00238 .name = "pcm_s8_planar",
00239 .type = AVMEDIA_TYPE_AUDIO,
00240 .id = CODEC_ID_PCM_S8_PLANAR,
00241 .priv_data_size = sizeof(EightSvxContext),
00242 .init = eightsvx_decode_init,
00243 .close = eightsvx_decode_close,
00244 .decode = eightsvx_decode_frame,
00245 .capabilities = CODEC_CAP_DELAY | CODEC_CAP_DR1,
00246 .long_name = NULL_IF_CONFIG_SMALL("PCM signed 8-bit planar"),
00247 };