libavcodec/nellymoserdec.c - vendor/opensource/ffmpeg - Git at Google

 /*
  * NellyMoser audio decoder
  * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
  *                    539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
  *                    520e17cd55896441042b14df2566a6eb610ed444
  * Copyright (c) 2007 Loic Minier <lool at dooz.org>
  *                    Benjamin Larsson
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  */

 /**
  * @file libavcodec/nellymoserdec.c
  * The 3 alphanumeric copyright notices are md5summed they are from the original
  * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
  */

 #include "nellymoser.h"
 #include "libavutil/lfg.h"
 #include "libavutil/random_seed.h"
 #include "avcodec.h"
 #include "dsputil.h"

 #define ALT_BITSTREAM_READER_LE
 #include "bitstream.h"


 typedef struct NellyMoserDecodeContext {
     AVCodecContext* avctx;
     DECLARE_ALIGNED_16(float,float_buf[NELLY_SAMPLES]);
     float           state[128];
     AVLFG           random_state;
     GetBitContext   gb;
     int             add_bias;
     float           scale_bias;
     DSPContext      dsp;
     MDCTContext     imdct_ctx;
     DECLARE_ALIGNED_16(float,imdct_out[NELLY_BUF_LEN * 2]);
 } NellyMoserDecodeContext;

 static void overlap_and_window(NellyMoserDecodeContext *s, float *state, float *audio, float *a_in)
 {
     int bot, top;

     bot = 0;
     top = NELLY_BUF_LEN-1;

     while (bot < NELLY_BUF_LEN) {
         audio[bot] = a_in [bot]*ff_sine_128[bot]
                     +state[bot]*ff_sine_128[top] + s->add_bias;

         bot++;
         top--;
     }
     memcpy(state, a_in + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
 }

 static void nelly_decode_block(NellyMoserDecodeContext *s,
                                const unsigned char block[NELLY_BLOCK_LEN],
                                float audio[NELLY_SAMPLES])
 {
     int i,j;
     float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
     float *aptr, *bptr, *pptr, val, pval;
     int bits[NELLY_BUF_LEN];
     unsigned char v;

     init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);

     bptr = buf;
     pptr = pows;
     val = ff_nelly_init_table[get_bits(&s->gb, 6)];
     for (i=0 ; i<NELLY_BANDS ; i++) {
         if (i > 0)
             val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
         pval = -pow(2, val/2048) * s->scale_bias;
         for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
             *bptr++ = val;
             *pptr++ = pval;
         }

     }

     ff_nelly_get_sample_bits(buf, bits);

     for (i = 0; i < 2; i++) {
         aptr = audio + i * NELLY_BUF_LEN;

         init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
         skip_bits(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);

         for (j = 0; j < NELLY_FILL_LEN; j++) {
             if (bits[j] <= 0) {
                 aptr[j] = M_SQRT1_2*pows[j];
                 if (av_lfg_get(&s->random_state) & 1)
                     aptr[j] *= -1.0;
             } else {
                 v = get_bits(&s->gb, bits[j]);
                 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
             }
         }
         memset(&aptr[NELLY_FILL_LEN], 0,
                (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));

         ff_imdct_calc(&s->imdct_ctx, s->imdct_out, aptr);
         /* XXX: overlapping and windowing should be part of a more
            generic imdct function */
         overlap_and_window(s, s->state, aptr, s->imdct_out);
     }
 }

 static av_cold int decode_init(AVCodecContext * avctx) {
     NellyMoserDecodeContext *s = avctx->priv_data;

     s->avctx = avctx;
     av_lfg_init(&s->random_state, ff_random_get_seed());
     ff_mdct_init(&s->imdct_ctx, 8, 1);

     dsputil_init(&s->dsp, avctx);

     if(s->dsp.float_to_int16 == ff_float_to_int16_c) {
         s->add_bias = 385;
         s->scale_bias = 1.0/(8*32768);
     } else {
         s->add_bias = 0;
         s->scale_bias = 1.0/(1*8);
     }

     /* Generate overlap window */
     if (!ff_sine_128[127])
         ff_sine_window_init(ff_sine_128, 128);

     avctx->sample_fmt = SAMPLE_FMT_S16;
     avctx->channel_layout = CH_LAYOUT_MONO;
     return 0;
 }

 static int decode_tag(AVCodecContext * avctx,
                       void *data, int *data_size,
                       const uint8_t * buf, int buf_size) {
     NellyMoserDecodeContext *s = avctx->priv_data;
     int data_max = *data_size;
     int blocks, i;
     int16_t* samples;
     *data_size = 0;
     samples = (int16_t*)data;

     if (buf_size < avctx->block_align)
         return buf_size;

     switch (buf_size) {
         case 64:    // 8000Hz
             blocks = 1; break;
         case 128:   // 11025Hz
             blocks = 2; break;
         case 256:   // 22050Hz
             blocks = 4; break;
         case 512:   // 44100Hz
             blocks = 8; break;
         default:
             av_log(avctx, AV_LOG_DEBUG, "Tag size %d.\n", buf_size);
             return buf_size;
     }

     for (i=0 ; i<blocks ; i++) {
         if ((i + 1) * NELLY_SAMPLES * sizeof(int16_t) > data_max)
             return i > 0 ? i * NELLY_BLOCK_LEN : -1;
         nelly_decode_block(s, &buf[i*NELLY_BLOCK_LEN], s->float_buf);
         s->dsp.float_to_int16(&samples[i*NELLY_SAMPLES], s->float_buf, NELLY_SAMPLES);
         *data_size += NELLY_SAMPLES*sizeof(int16_t);
     }

     return buf_size;
 }

 static av_cold int decode_end(AVCodecContext * avctx) {
     NellyMoserDecodeContext *s = avctx->priv_data;

     ff_mdct_end(&s->imdct_ctx);
     return 0;
 }

 AVCodec nellymoser_decoder = {
     "nellymoser",
     CODEC_TYPE_AUDIO,
     CODEC_ID_NELLYMOSER,
     sizeof(NellyMoserDecodeContext),
     decode_init,
     NULL,
     decode_end,
     decode_tag,
     .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
 };
	/*
	* NellyMoser audio decoder
	* Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
	* 539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
	* 520e17cd55896441042b14df2566a6eb610ed444
	* Copyright (c) 2007 Loic Minier <lool at dooz.org>
	* Benjamin Larsson
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
	* DEALINGS IN THE SOFTWARE.
	*/

	/**
	* @file libavcodec/nellymoserdec.c
	* The 3 alphanumeric copyright notices are md5summed they are from the original
	* implementors. The original code is available from http://code.google.com/p/nelly2pcm/
	*/

	#include "nellymoser.h"
	#include "libavutil/lfg.h"
	#include "libavutil/random_seed.h"
	#include "avcodec.h"
	#include "dsputil.h"

	#define ALT_BITSTREAM_READER_LE
	#include "bitstream.h"


	typedef struct NellyMoserDecodeContext {
	AVCodecContext* avctx;
	DECLARE_ALIGNED_16(float,float_buf[NELLY_SAMPLES]);
	float state[128];
	AVLFG random_state;
	GetBitContext gb;
	int add_bias;
	float scale_bias;
	DSPContext dsp;
	MDCTContext imdct_ctx;
	DECLARE_ALIGNED_16(float,imdct_out[NELLY_BUF_LEN * 2]);
	} NellyMoserDecodeContext;

	static void overlap_and_window(NellyMoserDecodeContext s, float state, float audio, float a_in)
	{
	int bot, top;

	bot = 0;
	top = NELLY_BUF_LEN-1;

	while (bot < NELLY_BUF_LEN) {
	audio[bot] = a_in [bot]*ff_sine_128[bot]
	+state[bot]*ff_sine_128[top] + s->add_bias;

	bot++;
	top--;
	}
	memcpy(state, a_in + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
	}

	static void nelly_decode_block(NellyMoserDecodeContext *s,
	const unsigned char block[NELLY_BLOCK_LEN],
	float audio[NELLY_SAMPLES])
	{
	int i,j;
	float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
	float aptr, bptr, *pptr, val, pval;
	int bits[NELLY_BUF_LEN];
	unsigned char v;

	init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);

	bptr = buf;
	pptr = pows;
	val = ff_nelly_init_table[get_bits(&s->gb, 6)];
	for (i=0 ; i<NELLY_BANDS ; i++) {
	if (i > 0)
	val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
	pval = -pow(2, val/2048) * s->scale_bias;
	for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
	*bptr++ = val;
	*pptr++ = pval;
	}

	}

	ff_nelly_get_sample_bits(buf, bits);

	for (i = 0; i < 2; i++) {
	aptr = audio + i * NELLY_BUF_LEN;

	init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
	skip_bits(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);

	for (j = 0; j < NELLY_FILL_LEN; j++) {
	if (bits[j] <= 0) {
	aptr[j] = M_SQRT1_2*pows[j];
	if (av_lfg_get(&s->random_state) & 1)
	aptr[j] *= -1.0;
	} else {
	v = get_bits(&s->gb, bits[j]);
	aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
	}
	}
	memset(&aptr[NELLY_FILL_LEN], 0,
	(NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));

	ff_imdct_calc(&s->imdct_ctx, s->imdct_out, aptr);
	/* XXX: overlapping and windowing should be part of a more
	generic imdct function */
	overlap_and_window(s, s->state, aptr, s->imdct_out);
	}
	}

	static av_cold int decode_init(AVCodecContext * avctx) {
	NellyMoserDecodeContext *s = avctx->priv_data;

	s->avctx = avctx;
	av_lfg_init(&s->random_state, ff_random_get_seed());
	ff_mdct_init(&s->imdct_ctx, 8, 1);

	dsputil_init(&s->dsp, avctx);

	if(s->dsp.float_to_int16 == ff_float_to_int16_c) {
	s->add_bias = 385;
	s->scale_bias = 1.0/(8*32768);
	} else {
	s->add_bias = 0;
	s->scale_bias = 1.0/(1*8);
	}

	/* Generate overlap window */
	if (!ff_sine_128[127])
	ff_sine_window_init(ff_sine_128, 128);

	avctx->sample_fmt = SAMPLE_FMT_S16;
	avctx->channel_layout = CH_LAYOUT_MONO;
	return 0;
	}

	static int decode_tag(AVCodecContext * avctx,
	void data, int data_size,
	const uint8_t * buf, int buf_size) {
	NellyMoserDecodeContext *s = avctx->priv_data;
	int data_max = *data_size;
	int blocks, i;
	int16_t* samples;
	*data_size = 0;
	samples = (int16_t*)data;

	if (buf_size < avctx->block_align)
	return buf_size;

	switch (buf_size) {
	case 64: // 8000Hz
	blocks = 1; break;
	case 128: // 11025Hz
	blocks = 2; break;
	case 256: // 22050Hz
	blocks = 4; break;
	case 512: // 44100Hz
	blocks = 8; break;
	default:
	av_log(avctx, AV_LOG_DEBUG, "Tag size %d.\n", buf_size);
	return buf_size;
	}

	for (i=0 ; i<blocks ; i++) {
	if ((i + 1) * NELLY_SAMPLES * sizeof(int16_t) > data_max)
	return i > 0 ? i * NELLY_BLOCK_LEN : -1;
	nelly_decode_block(s, &buf[i*NELLY_BLOCK_LEN], s->float_buf);
	s->dsp.float_to_int16(&samples[i*NELLY_SAMPLES], s->float_buf, NELLY_SAMPLES);
	data_size += NELLY_SAMPLESsizeof(int16_t);
	}

	return buf_size;
	}

	static av_cold int decode_end(AVCodecContext * avctx) {
	NellyMoserDecodeContext *s = avctx->priv_data;

	ff_mdct_end(&s->imdct_ctx);
	return 0;
	}

	AVCodec nellymoser_decoder = {
	"nellymoser",
	CODEC_TYPE_AUDIO,
	CODEC_ID_NELLYMOSER,
	sizeof(NellyMoserDecodeContext),
	decode_init,
	NULL,
	decode_end,
	decode_tag,
	.long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
	};