libavcodec/nellymoserdec.c
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00001 /*
00002  * NellyMoser audio decoder
00003  * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
00004  *                    539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
00005  *                    520e17cd55896441042b14df2566a6eb610ed444
00006  * Copyright (c) 2007 Loic Minier <lool at dooz.org>
00007  *                    Benjamin Larsson
00008  *
00009  * Permission is hereby granted, free of charge, to any person obtaining a
00010  * copy of this software and associated documentation files (the "Software"),
00011  * to deal in the Software without restriction, including without limitation
00012  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
00013  * and/or sell copies of the Software, and to permit persons to whom the
00014  * Software is furnished to do so, subject to the following conditions:
00015  *
00016  * The above copyright notice and this permission notice shall be included in
00017  * all copies or substantial portions of the Software.
00018  *
00019  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00020  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00021  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
00022  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00023  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
00024  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
00025  * DEALINGS IN THE SOFTWARE.
00026  */
00027 
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 "dsputil.h"
00040 #include "fft.h"
00041 #include "fmtconvert.h"
00042 #include "sinewin.h"
00043 
00044 #define BITSTREAM_READER_LE
00045 #include "get_bits.h"
00046 
00047 
00048 typedef struct NellyMoserDecodeContext {
00049     AVCodecContext* avctx;
00050     AVFrame         frame;
00051     float          *float_buf;
00052     DECLARE_ALIGNED(16, float, state)[NELLY_BUF_LEN];
00053     AVLFG           random_state;
00054     GetBitContext   gb;
00055     float           scale_bias;
00056     DSPContext      dsp;
00057     FFTContext      imdct_ctx;
00058     FmtConvertContext fmt_conv;
00059     DECLARE_ALIGNED(32, float, imdct_out)[NELLY_BUF_LEN * 2];
00060 } NellyMoserDecodeContext;
00061 
00062 static void nelly_decode_block(NellyMoserDecodeContext *s,
00063                                const unsigned char block[NELLY_BLOCK_LEN],
00064                                float audio[NELLY_SAMPLES])
00065 {
00066     int i,j;
00067     float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
00068     float *aptr, *bptr, *pptr, val, pval;
00069     int bits[NELLY_BUF_LEN];
00070     unsigned char v;
00071 
00072     init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
00073 
00074     bptr = buf;
00075     pptr = pows;
00076     val = ff_nelly_init_table[get_bits(&s->gb, 6)];
00077     for (i=0 ; i<NELLY_BANDS ; i++) {
00078         if (i > 0)
00079             val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
00080         pval = -pow(2, val/2048) * s->scale_bias;
00081         for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
00082             *bptr++ = val;
00083             *pptr++ = pval;
00084         }
00085 
00086     }
00087 
00088     ff_nelly_get_sample_bits(buf, bits);
00089 
00090     for (i = 0; i < 2; i++) {
00091         aptr = audio + i * NELLY_BUF_LEN;
00092 
00093         init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
00094         skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
00095 
00096         for (j = 0; j < NELLY_FILL_LEN; j++) {
00097             if (bits[j] <= 0) {
00098                 aptr[j] = M_SQRT1_2*pows[j];
00099                 if (av_lfg_get(&s->random_state) & 1)
00100                     aptr[j] *= -1.0;
00101             } else {
00102                 v = get_bits(&s->gb, bits[j]);
00103                 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
00104             }
00105         }
00106         memset(&aptr[NELLY_FILL_LEN], 0,
00107                (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
00108 
00109         s->imdct_ctx.imdct_calc(&s->imdct_ctx, s->imdct_out, aptr);
00110         /* XXX: overlapping and windowing should be part of a more
00111            generic imdct function */
00112         s->dsp.vector_fmul_reverse(s->state, s->state, ff_sine_128, NELLY_BUF_LEN);
00113         s->dsp.vector_fmul_add(aptr, s->imdct_out, ff_sine_128, s->state, NELLY_BUF_LEN);
00114         memcpy(s->state, s->imdct_out + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
00115     }
00116 }
00117 
00118 static av_cold int decode_init(AVCodecContext * avctx) {
00119     NellyMoserDecodeContext *s = avctx->priv_data;
00120 
00121     s->avctx = avctx;
00122     av_lfg_init(&s->random_state, 0);
00123     ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
00124 
00125     dsputil_init(&s->dsp, avctx);
00126 
00127     if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
00128         s->scale_bias = 1.0/(32768*8);
00129         avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
00130     } else {
00131         s->scale_bias = 1.0/(1*8);
00132         avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00133         ff_fmt_convert_init(&s->fmt_conv, avctx);
00134         s->float_buf = av_mallocz(NELLY_SAMPLES * sizeof(*s->float_buf));
00135         if (!s->float_buf) {
00136             av_log(avctx, AV_LOG_ERROR, "error allocating float buffer\n");
00137             return AVERROR(ENOMEM);
00138         }
00139     }
00140 
00141     /* Generate overlap window */
00142     if (!ff_sine_128[127])
00143         ff_init_ff_sine_windows(7);
00144 
00145     avctx->channel_layout = AV_CH_LAYOUT_MONO;
00146 
00147     avcodec_get_frame_defaults(&s->frame);
00148     avctx->coded_frame = &s->frame;
00149 
00150     return 0;
00151 }
00152 
00153 static int decode_tag(AVCodecContext *avctx, void *data,
00154                       int *got_frame_ptr, AVPacket *avpkt)
00155 {
00156     const uint8_t *buf = avpkt->data;
00157     const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
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 
00166     if (blocks <= 0) {
00167         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
00168         return AVERROR_INVALIDDATA;
00169     }
00170 
00171     if (buf_size % NELLY_BLOCK_LEN) {
00172         av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
00173                buf_size % NELLY_BLOCK_LEN);
00174     }
00175     /* Normal numbers of blocks for sample rates:
00176      *  8000 Hz - 1
00177      * 11025 Hz - 2
00178      * 16000 Hz - 3
00179      * 22050 Hz - 4
00180      * 44100 Hz - 8
00181      */
00182     if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
00183         avctx->sample_rate= 11025*(blocks/2);
00184 
00185     /* get output buffer */
00186     s->frame.nb_samples = NELLY_SAMPLES * blocks;
00187     if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
00188         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00189         return ret;
00190     }
00191     samples_s16 = (int16_t *)s->frame.data[0];
00192     samples_flt = (float   *)s->frame.data[0];
00193 
00194     for (i=0 ; i<blocks ; i++) {
00195         if (avctx->sample_fmt == AV_SAMPLE_FMT_FLT) {
00196             nelly_decode_block(s, buf, samples_flt);
00197             samples_flt += NELLY_SAMPLES;
00198         } else {
00199             nelly_decode_block(s, buf, s->float_buf);
00200             s->fmt_conv.float_to_int16(samples_s16, s->float_buf, NELLY_SAMPLES);
00201             samples_s16 += NELLY_SAMPLES;
00202         }
00203         buf += NELLY_BLOCK_LEN;
00204     }
00205 
00206     *got_frame_ptr   = 1;
00207     *(AVFrame *)data = s->frame;
00208 
00209     return buf_size;
00210 }
00211 
00212 static av_cold int decode_end(AVCodecContext * avctx) {
00213     NellyMoserDecodeContext *s = avctx->priv_data;
00214 
00215     av_freep(&s->float_buf);
00216     ff_mdct_end(&s->imdct_ctx);
00217 
00218     return 0;
00219 }
00220 
00221 AVCodec ff_nellymoser_decoder = {
00222     .name           = "nellymoser",
00223     .type           = AVMEDIA_TYPE_AUDIO,
00224     .id             = CODEC_ID_NELLYMOSER,
00225     .priv_data_size = sizeof(NellyMoserDecodeContext),
00226     .init           = decode_init,
00227     .close          = decode_end,
00228     .decode         = decode_tag,
00229     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
00230     .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
00231     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
00232                                                       AV_SAMPLE_FMT_S16,
00233                                                       AV_SAMPLE_FMT_NONE },
00234 };
00235