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00034 #include "nellymoser.h"
00035 #include "libavutil/lfg.h"
00036 #include "libavutil/random_seed.h"
00037 #include "libavutil/audioconvert.h"
00038 #include "avcodec.h"
00039 #include "internal.h"
00040 #include "dsputil.h"
00041 #include "fft.h"
00042 #include "fmtconvert.h"
00043 #include "sinewin.h"
00044
00045 #define BITSTREAM_READER_LE
00046 #include "get_bits.h"
00047
00048
00049 typedef struct NellyMoserDecodeContext {
00050 AVCodecContext* avctx;
00051 AVFrame frame;
00052 float *float_buf;
00053 DECLARE_ALIGNED(16, float, state)[NELLY_BUF_LEN];
00054 AVLFG random_state;
00055 GetBitContext gb;
00056 float scale_bias;
00057 DSPContext dsp;
00058 FFTContext imdct_ctx;
00059 FmtConvertContext fmt_conv;
00060 DECLARE_ALIGNED(32, float, imdct_out)[NELLY_BUF_LEN * 2];
00061 } NellyMoserDecodeContext;
00062
00063 static void nelly_decode_block(NellyMoserDecodeContext *s,
00064 const unsigned char block[NELLY_BLOCK_LEN],
00065 float audio[NELLY_SAMPLES])
00066 {
00067 int i,j;
00068 float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
00069 float *aptr, *bptr, *pptr, val, pval;
00070 int bits[NELLY_BUF_LEN];
00071 unsigned char v;
00072
00073 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
00074
00075 bptr = buf;
00076 pptr = pows;
00077 val = ff_nelly_init_table[get_bits(&s->gb, 6)];
00078 for (i=0 ; i<NELLY_BANDS ; i++) {
00079 if (i > 0)
00080 val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
00081 pval = -pow(2, val/2048) * s->scale_bias;
00082 for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
00083 *bptr++ = val;
00084 *pptr++ = pval;
00085 }
00086
00087 }
00088
00089 ff_nelly_get_sample_bits(buf, bits);
00090
00091 for (i = 0; i < 2; i++) {
00092 aptr = audio + i * NELLY_BUF_LEN;
00093
00094 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
00095 skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
00096
00097 for (j = 0; j < NELLY_FILL_LEN; j++) {
00098 if (bits[j] <= 0) {
00099 aptr[j] = M_SQRT1_2*pows[j];
00100 if (av_lfg_get(&s->random_state) & 1)
00101 aptr[j] *= -1.0;
00102 } else {
00103 v = get_bits(&s->gb, bits[j]);
00104 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
00105 }
00106 }
00107 memset(&aptr[NELLY_FILL_LEN], 0,
00108 (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
00109
00110 s->imdct_ctx.imdct_calc(&s->imdct_ctx, s->imdct_out, aptr);
00111
00112
00113 s->dsp.vector_fmul_reverse(s->state, s->state, ff_sine_128, NELLY_BUF_LEN);
00114 s->dsp.vector_fmul_add(aptr, s->imdct_out, ff_sine_128, s->state, NELLY_BUF_LEN);
00115 memcpy(s->state, s->imdct_out + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
00116 }
00117 }
00118
00119 static av_cold int decode_init(AVCodecContext * avctx) {
00120 NellyMoserDecodeContext *s = avctx->priv_data;
00121
00122 s->avctx = avctx;
00123 av_lfg_init(&s->random_state, 0);
00124 ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
00125
00126 dsputil_init(&s->dsp, avctx);
00127
00128 if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
00129 s->scale_bias = 1.0/(32768*8);
00130 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
00131 } else {
00132 s->scale_bias = 1.0/(1*8);
00133 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00134 ff_fmt_convert_init(&s->fmt_conv, avctx);
00135 s->float_buf = av_mallocz(NELLY_SAMPLES * sizeof(*s->float_buf));
00136 if (!s->float_buf) {
00137 av_log(avctx, AV_LOG_ERROR, "error allocating float buffer\n");
00138 return AVERROR(ENOMEM);
00139 }
00140 }
00141
00142
00143 if (!ff_sine_128[127])
00144 ff_init_ff_sine_windows(7);
00145
00146 avctx->channel_layout = AV_CH_LAYOUT_MONO;
00147
00148 avcodec_get_frame_defaults(&s->frame);
00149 avctx->coded_frame = &s->frame;
00150
00151 return 0;
00152 }
00153
00154 static int decode_tag(AVCodecContext *avctx, void *data,
00155 int *got_frame_ptr, AVPacket *avpkt)
00156 {
00157 const uint8_t *buf = avpkt->data;
00158 int buf_size = avpkt->size;
00159 NellyMoserDecodeContext *s = avctx->priv_data;
00160 int blocks, i, ret;
00161 int16_t *samples_s16;
00162 float *samples_flt;
00163
00164 blocks = buf_size / NELLY_BLOCK_LEN;
00165 if (blocks <= 0) {
00166 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
00167 return AVERROR_INVALIDDATA;
00168 }
00169 if (buf_size % NELLY_BLOCK_LEN) {
00170 av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
00171 buf_size % NELLY_BLOCK_LEN);
00172 }
00173
00174
00175
00176
00177
00178
00179
00180
00181
00182 s->frame.nb_samples = NELLY_SAMPLES * blocks;
00183 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
00184 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00185 return ret;
00186 }
00187 samples_s16 = (int16_t *)s->frame.data[0];
00188 samples_flt = (float *)s->frame.data[0];
00189
00190 for (i=0 ; i<blocks ; i++) {
00191 if (avctx->sample_fmt == AV_SAMPLE_FMT_FLT) {
00192 nelly_decode_block(s, buf, samples_flt);
00193 samples_flt += NELLY_SAMPLES;
00194 } else {
00195 nelly_decode_block(s, buf, s->float_buf);
00196 s->fmt_conv.float_to_int16(samples_s16, s->float_buf, NELLY_SAMPLES);
00197 samples_s16 += NELLY_SAMPLES;
00198 }
00199 buf += NELLY_BLOCK_LEN;
00200 }
00201
00202 *got_frame_ptr = 1;
00203 *(AVFrame *)data = s->frame;
00204
00205 return buf_size;
00206 }
00207
00208 static av_cold int decode_end(AVCodecContext * avctx) {
00209 NellyMoserDecodeContext *s = avctx->priv_data;
00210
00211 av_freep(&s->float_buf);
00212 ff_mdct_end(&s->imdct_ctx);
00213
00214 return 0;
00215 }
00216
00217 AVCodec ff_nellymoser_decoder = {
00218 .name = "nellymoser",
00219 .type = AVMEDIA_TYPE_AUDIO,
00220 .id = CODEC_ID_NELLYMOSER,
00221 .priv_data_size = sizeof(NellyMoserDecodeContext),
00222 .init = decode_init,
00223 .close = decode_end,
00224 .decode = decode_tag,
00225 .capabilities = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
00226 .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
00227 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
00228 AV_SAMPLE_FMT_S16,
00229 AV_SAMPLE_FMT_NONE },
00230 };
00231