yading@10: /*
yading@10:  * NellyMoser audio decoder
yading@10:  * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
yading@10:  *                    539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
yading@10:  *                    520e17cd55896441042b14df2566a6eb610ed444
yading@10:  * Copyright (c) 2007 Loic Minier <lool at dooz.org>
yading@10:  *                    Benjamin Larsson
yading@10:  *
yading@10:  * Permission is hereby granted, free of charge, to any person obtaining a
yading@10:  * copy of this software and associated documentation files (the "Software"),
yading@10:  * to deal in the Software without restriction, including without limitation
yading@10:  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
yading@10:  * and/or sell copies of the Software, and to permit persons to whom the
yading@10:  * Software is furnished to do so, subject to the following conditions:
yading@10:  *
yading@10:  * The above copyright notice and this permission notice shall be included in
yading@10:  * all copies or substantial portions of the Software.
yading@10:  *
yading@10:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
yading@10:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
yading@10:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
yading@10:  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
yading@10:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
yading@10:  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
yading@10:  * DEALINGS IN THE SOFTWARE.
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * The 3 alphanumeric copyright notices are md5summed they are from the original
yading@10:  * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
yading@10:  */
yading@10: 
yading@10: #include "libavutil/channel_layout.h"
yading@10: #include "libavutil/float_dsp.h"
yading@10: #include "libavutil/lfg.h"
yading@10: #include "libavutil/random_seed.h"
yading@10: #include "avcodec.h"
yading@10: #include "fft.h"
yading@10: #include "fmtconvert.h"
yading@10: #include "internal.h"
yading@10: #include "nellymoser.h"
yading@10: #include "sinewin.h"
yading@10: 
yading@10: #define BITSTREAM_READER_LE
yading@10: #include "get_bits.h"
yading@10: 
yading@10: 
yading@10: typedef struct NellyMoserDecodeContext {
yading@10:     AVCodecContext* avctx;
yading@10:     AVLFG           random_state;
yading@10:     GetBitContext   gb;
yading@10:     float           scale_bias;
yading@10:     AVFloatDSPContext fdsp;
yading@10:     FFTContext      imdct_ctx;
yading@10:     DECLARE_ALIGNED(32, float, imdct_buf)[2][NELLY_BUF_LEN];
yading@10:     float          *imdct_out;
yading@10:     float          *imdct_prev;
yading@10: } NellyMoserDecodeContext;
yading@10: 
yading@10: static void nelly_decode_block(NellyMoserDecodeContext *s,
yading@10:                                const unsigned char block[NELLY_BLOCK_LEN],
yading@10:                                float audio[NELLY_SAMPLES])
yading@10: {
yading@10:     int i,j;
yading@10:     float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
yading@10:     float *aptr, *bptr, *pptr, val, pval;
yading@10:     int bits[NELLY_BUF_LEN];
yading@10:     unsigned char v;
yading@10: 
yading@10:     init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
yading@10: 
yading@10:     bptr = buf;
yading@10:     pptr = pows;
yading@10:     val = ff_nelly_init_table[get_bits(&s->gb, 6)];
yading@10:     for (i=0 ; i<NELLY_BANDS ; i++) {
yading@10:         if (i > 0)
yading@10:             val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
yading@10:         pval = -pow(2, val/2048) * s->scale_bias;
yading@10:         for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
yading@10:             *bptr++ = val;
yading@10:             *pptr++ = pval;
yading@10:         }
yading@10: 
yading@10:     }
yading@10: 
yading@10:     ff_nelly_get_sample_bits(buf, bits);
yading@10: 
yading@10:     for (i = 0; i < 2; i++) {
yading@10:         aptr = audio + i * NELLY_BUF_LEN;
yading@10: 
yading@10:         init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
yading@10:         skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
yading@10: 
yading@10:         for (j = 0; j < NELLY_FILL_LEN; j++) {
yading@10:             if (bits[j] <= 0) {
yading@10:                 aptr[j] = M_SQRT1_2*pows[j];
yading@10:                 if (av_lfg_get(&s->random_state) & 1)
yading@10:                     aptr[j] *= -1.0;
yading@10:             } else {
yading@10:                 v = get_bits(&s->gb, bits[j]);
yading@10:                 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
yading@10:             }
yading@10:         }
yading@10:         memset(&aptr[NELLY_FILL_LEN], 0,
yading@10:                (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
yading@10: 
yading@10:         s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);
yading@10:         s->fdsp.vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN / 2,
yading@10:                                    s->imdct_out, ff_sine_128,
yading@10:                                    NELLY_BUF_LEN / 2);
yading@10:         FFSWAP(float *, s->imdct_out, s->imdct_prev);
yading@10:     }
yading@10: }
yading@10: 
yading@10: static av_cold int decode_init(AVCodecContext * avctx) {
yading@10:     NellyMoserDecodeContext *s = avctx->priv_data;
yading@10: 
yading@10:     s->avctx = avctx;
yading@10:     s->imdct_out = s->imdct_buf[0];
yading@10:     s->imdct_prev = s->imdct_buf[1];
yading@10:     av_lfg_init(&s->random_state, 0);
yading@10:     ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
yading@10: 
yading@10:     avpriv_float_dsp_init(&s->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
yading@10: 
yading@10:     s->scale_bias = 1.0/(32768*8);
yading@10:     avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
yading@10: 
yading@10:     /* Generate overlap window */
yading@10:     if (!ff_sine_128[127])
yading@10:         ff_init_ff_sine_windows(7);
yading@10: 
yading@10:     avctx->channels       = 1;
yading@10:     avctx->channel_layout = AV_CH_LAYOUT_MONO;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int decode_tag(AVCodecContext *avctx, void *data,
yading@10:                       int *got_frame_ptr, AVPacket *avpkt)
yading@10: {
yading@10:     AVFrame *frame     = data;
yading@10:     const uint8_t *buf = avpkt->data;
yading@10:     const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
yading@10:     int buf_size = avpkt->size;
yading@10:     NellyMoserDecodeContext *s = avctx->priv_data;
yading@10:     int blocks, i, ret;
yading@10:     float   *samples_flt;
yading@10: 
yading@10:     blocks     = buf_size / NELLY_BLOCK_LEN;
yading@10: 
yading@10:     if (blocks <= 0) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     if (buf_size % NELLY_BLOCK_LEN) {
yading@10:         av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
yading@10:                buf_size % NELLY_BLOCK_LEN);
yading@10:     }
yading@10:     /* Normal numbers of blocks for sample rates:
yading@10:      *  8000 Hz - 1
yading@10:      * 11025 Hz - 2
yading@10:      * 16000 Hz - 3
yading@10:      * 22050 Hz - 4
yading@10:      * 44100 Hz - 8
yading@10:      */
yading@10:     if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
yading@10:         avctx->sample_rate= 11025*(blocks/2);
yading@10: 
yading@10:     /* get output buffer */
yading@10:     frame->nb_samples = NELLY_SAMPLES * blocks;
yading@10:     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
yading@10:         return ret;
yading@10:     samples_flt = (float *)frame->data[0];
yading@10: 
yading@10:     for (i=0 ; i<blocks ; i++) {
yading@10:         nelly_decode_block(s, buf, samples_flt);
yading@10:         samples_flt += NELLY_SAMPLES;
yading@10:         buf += NELLY_BLOCK_LEN;
yading@10:     }
yading@10: 
yading@10:     *got_frame_ptr = 1;
yading@10: 
yading@10:     return buf_size;
yading@10: }
yading@10: 
yading@10: static av_cold int decode_end(AVCodecContext * avctx) {
yading@10:     NellyMoserDecodeContext *s = avctx->priv_data;
yading@10: 
yading@10:     ff_mdct_end(&s->imdct_ctx);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_nellymoser_decoder = {
yading@10:     .name           = "nellymoser",
yading@10:     .type           = AVMEDIA_TYPE_AUDIO,
yading@10:     .id             = AV_CODEC_ID_NELLYMOSER,
yading@10:     .priv_data_size = sizeof(NellyMoserDecodeContext),
yading@10:     .init           = decode_init,
yading@10:     .close          = decode_end,
yading@10:     .decode         = decode_tag,
yading@10:     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
yading@10:     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
yading@10:                                                       AV_SAMPLE_FMT_NONE },
yading@10: };