libavcodec/nellymoserdec.c

   1 /*
   2  * NellyMoser audio decoder
   3  * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
   4  *                    539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
   5  *                    520e17cd55896441042b14df2566a6eb610ed444
   6  * Copyright (c) 2007 Loic Minier <lool at dooz.org>
   7  *                    Benjamin Larsson
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  24  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25  * DEALINGS IN THE SOFTWARE.
  26  */
  27
  28 /**
  29  * @file
  30  * The 3 alphanumeric copyright notices are md5summed they are from the original
  31  * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
  32  */
  33
  34 #include "nellymoser.h"
  35 #include "libavutil/lfg.h"
  36 #include "libavutil/random_seed.h"
  37 #include "libavutil/audioconvert.h"
  38 #include "avcodec.h"
  39 #include "dsputil.h"
  40 #include "fft.h"
  41 #include "fmtconvert.h"
  42 #include "sinewin.h"
  43
  44 #define ALT_BITSTREAM_READER_LE
  45 #include "get_bits.h"
  46
  47
  48 typedef struct NellyMoserDecodeContext {
  49     AVCodecContext* avctx;
  50     AVFrame         frame;
  51     float          *float_buf;
  52     DECLARE_ALIGNED(16, float, state)[NELLY_BUF_LEN];
  53     AVLFG           random_state;
  54     GetBitContext   gb;
  55     float           scale_bias;
  56     DSPContext      dsp;
  57     FFTContext      imdct_ctx;
  58     FmtConvertContext fmt_conv;
  59     DECLARE_ALIGNED(32, float, imdct_out)[NELLY_BUF_LEN * 2];
  60 } NellyMoserDecodeContext;
  61
  62 static void nelly_decode_block(NellyMoserDecodeContext *s,
  63                                const unsigned char block[NELLY_BLOCK_LEN],
  64                                float audio[NELLY_SAMPLES])
  65 {
  66     int i,j;
  67     float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
  68     float *aptr, *bptr, *pptr, val, pval;
  69     int bits[NELLY_BUF_LEN];
  70     unsigned char v;
  71
  72     init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
  73
  74     bptr = buf;
  75     pptr = pows;
  76     val = ff_nelly_init_table[get_bits(&s->gb, 6)];
  77     for (i=0 ; i<NELLY_BANDS ; i++) {
  78         if (i > 0)
  79             val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
  80         pval = -pow(2, val/2048) * s->scale_bias;
  81         for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
  82             *bptr++ = val;
  83             *pptr++ = pval;
  84         }
  85
  86     }
  87
  88     ff_nelly_get_sample_bits(buf, bits);
  89
  90     for (i = 0; i < 2; i++) {
  91         aptr = audio + i * NELLY_BUF_LEN;
  92
  93         init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
  94         skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
  95
  96         for (j = 0; j < NELLY_FILL_LEN; j++) {
  97             if (bits[j] <= 0) {
  98                 aptr[j] = M_SQRT1_2*pows[j];
  99                 if (av_lfg_get(&s->random_state) & 1)
 100                     aptr[j] *= -1.0;
 101             } else {
 102                 v = get_bits(&s->gb, bits[j]);
 103                 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
 104             }
 105         }
 106         memset(&aptr[NELLY_FILL_LEN], 0,
 107                (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
 108
 109         s->imdct_ctx.imdct_calc(&s->imdct_ctx, s->imdct_out, aptr);
 110         /* XXX: overlapping and windowing should be part of a more
 111            generic imdct function */
 112         s->dsp.vector_fmul_reverse(s->state, s->state, ff_sine_128, NELLY_BUF_LEN);
 113         s->dsp.vector_fmul_add(aptr, s->imdct_out, ff_sine_128, s->state, NELLY_BUF_LEN);
 114         memcpy(s->state, s->imdct_out + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
 115     }
 116 }
 117
 118 static av_cold int decode_init(AVCodecContext * avctx) {
 119     NellyMoserDecodeContext *s = avctx->priv_data;
 120
 121     s->avctx = avctx;
 122     av_lfg_init(&s->random_state, 0);
 123     ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
 124
 125     dsputil_init(&s->dsp, avctx);
 126
 127     if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
 128         s->scale_bias = 1.0/(32768*8);
 129         avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
 130     } else {
 131         s->scale_bias = 1.0/(1*8);
 132         avctx->sample_fmt = AV_SAMPLE_FMT_S16;
 133         ff_fmt_convert_init(&s->fmt_conv, avctx);
 134         s->float_buf = av_mallocz(NELLY_SAMPLES * sizeof(*s->float_buf));
 135         if (!s->float_buf) {
 136             av_log(avctx, AV_LOG_ERROR, "error allocating float buffer\n");
 137             return AVERROR(ENOMEM);
 138         }
 139     }
 140
 141     /* Generate overlap window */
 142     if (!ff_sine_128[127])
 143         ff_init_ff_sine_windows(7);
 144
 145     avctx->channel_layout = AV_CH_LAYOUT_MONO;
 146
 147     avcodec_get_frame_defaults(&s->frame);
 148     avctx->coded_frame = &s->frame;
 149
 150     return 0;
 151 }
 152
 153 static int decode_tag(AVCodecContext *avctx, void *data,
 154                       int *got_frame_ptr, AVPacket *avpkt)
 155 {
 156     const uint8_t *buf = avpkt->data;
 157     int buf_size = avpkt->size;
 158     NellyMoserDecodeContext *s = avctx->priv_data;
 159     int blocks, i, ret;
 160     int16_t *samples_s16;
 161     float   *samples_flt;
 162
 163     blocks     = buf_size / NELLY_BLOCK_LEN;
 164     if (blocks <= 0) {
 165         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
 166         return AVERROR_INVALIDDATA;
 167     }
 168     if (buf_size % NELLY_BLOCK_LEN) {
 169         av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
 170                buf_size % NELLY_BLOCK_LEN);
 171     }
 172     /* Normal numbers of blocks for sample rates:
 173      *  8000 Hz - 1
 174      * 11025 Hz - 2
 175      * 16000 Hz - 3
 176      * 22050 Hz - 4
 177      * 44100 Hz - 8
 178      */
 179
 180     /* get output buffer */
 181     s->frame.nb_samples = NELLY_SAMPLES * blocks;
 182     if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
 183         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 184         return ret;
 185     }
 186     samples_s16 = (int16_t *)s->frame.data[0];
 187     samples_flt = (float   *)s->frame.data[0];
 188
 189     for (i=0 ; i<blocks ; i++) {
 190         if (avctx->sample_fmt == SAMPLE_FMT_FLT) {
 191             nelly_decode_block(s, buf, samples_flt);
 192             samples_flt += NELLY_SAMPLES;
 193         } else {
 194             nelly_decode_block(s, buf, s->float_buf);
 195             s->fmt_conv.float_to_int16(samples_s16, s->float_buf, NELLY_SAMPLES);
 196             samples_s16 += NELLY_SAMPLES;
 197         }
 198         buf += NELLY_BLOCK_LEN;
 199     }
 200
 201     *got_frame_ptr   = 1;
 202     *(AVFrame *)data = s->frame;
 203
 204     return buf_size;
 205 }
 206
 207 static av_cold int decode_end(AVCodecContext * avctx) {
 208     NellyMoserDecodeContext *s = avctx->priv_data;
 209
 210     av_freep(&s->float_buf);
 211     ff_mdct_end(&s->imdct_ctx);
 212
 213     return 0;
 214 }
 215
 216 AVCodec ff_nellymoser_decoder = {
 217     .name           = "nellymoser",
 218     .type           = AVMEDIA_TYPE_AUDIO,
 219     .id             = CODEC_ID_NELLYMOSER,
 220     .priv_data_size = sizeof(NellyMoserDecodeContext),
 221     .init           = decode_init,
 222     .close          = decode_end,
 223     .decode         = decode_tag,
 224     .capabilities   = CODEC_CAP_DR1,
 225     .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
 226     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
 227                                                       AV_SAMPLE_FMT_S16,
 228                                                       AV_SAMPLE_FMT_NONE },
 229 };
 230