libavcodec/nellymoserdec.c - third_party/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
  * 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 "libavutil/audioconvert.h"
 #include "avcodec.h"
 #include "dsputil.h"
 #include "fft.h"
 #include "fmtconvert.h"
 #include "sinewin.h"

 #define BITSTREAM_READER_LE
 #include "get_bits.h"


 typedef struct NellyMoserDecodeContext {
     AVCodecContext* avctx;
     AVFrame         frame;
     float          *float_buf;
     DECLARE_ALIGNED(16, float, state)[NELLY_BUF_LEN];
     AVLFG           random_state;
     GetBitContext   gb;
     float           scale_bias;
     DSPContext      dsp;
     FFTContext      imdct_ctx;
     FmtConvertContext fmt_conv;
     DECLARE_ALIGNED(32, float, imdct_out)[NELLY_BUF_LEN * 2];
 } NellyMoserDecodeContext;

 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_long(&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));

         s->imdct_ctx.imdct_calc(&s->imdct_ctx, s->imdct_out, aptr);
         /* XXX: overlapping and windowing should be part of a more
            generic imdct function */
         s->dsp.vector_fmul_reverse(s->state, s->state, ff_sine_128, NELLY_BUF_LEN);
         s->dsp.vector_fmul_add(aptr, s->imdct_out, ff_sine_128, s->state, NELLY_BUF_LEN);
         memcpy(s->state, s->imdct_out + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
     }
 }

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

     s->avctx = avctx;
     av_lfg_init(&s->random_state, 0);
     ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);

     dsputil_init(&s->dsp, avctx);

     if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
         s->scale_bias = 1.0/(32768*8);
         avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
     } else {
         s->scale_bias = 1.0/(1*8);
         avctx->sample_fmt = AV_SAMPLE_FMT_S16;
         ff_fmt_convert_init(&s->fmt_conv, avctx);
         s->float_buf = av_mallocz(NELLY_SAMPLES * sizeof(*s->float_buf));
         if (!s->float_buf) {
             av_log(avctx, AV_LOG_ERROR, "error allocating float buffer\n");
             return AVERROR(ENOMEM);
         }
     }

     /* Generate overlap window */
     if (!ff_sine_128[127])
         ff_init_ff_sine_windows(7);

     avctx->channel_layout = AV_CH_LAYOUT_MONO;

     avcodec_get_frame_defaults(&s->frame);
     avctx->coded_frame = &s->frame;

     return 0;
 }

 static int decode_tag(AVCodecContext *avctx, void *data,
                       int *got_frame_ptr, AVPacket *avpkt)
 {
     const uint8_t *buf = avpkt->data;
     const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
     int buf_size = avpkt->size;
     NellyMoserDecodeContext *s = avctx->priv_data;
     int blocks, i, ret;
     int16_t *samples_s16;
     float   *samples_flt;

     blocks     = buf_size / NELLY_BLOCK_LEN;

     if (blocks <= 0) {
         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
         return AVERROR_INVALIDDATA;
     }

     if (buf_size % NELLY_BLOCK_LEN) {
         av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
                buf_size % NELLY_BLOCK_LEN);
     }
     /* Normal numbers of blocks for sample rates:
      *  8000 Hz - 1
      * 11025 Hz - 2
      * 16000 Hz - 3
      * 22050 Hz - 4
      * 44100 Hz - 8
      */
     if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
         avctx->sample_rate= 11025*(blocks/2);

     /* get output buffer */
     s->frame.nb_samples = NELLY_SAMPLES * blocks;
     if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return ret;
     }
     samples_s16 = (int16_t *)s->frame.data[0];
     samples_flt = (float   *)s->frame.data[0];

     for (i=0 ; i<blocks ; i++) {
         if (avctx->sample_fmt == AV_SAMPLE_FMT_FLT) {
             nelly_decode_block(s, buf, samples_flt);
             samples_flt += NELLY_SAMPLES;
         } else {
             nelly_decode_block(s, buf, s->float_buf);
             s->fmt_conv.float_to_int16(samples_s16, s->float_buf, NELLY_SAMPLES);
             samples_s16 += NELLY_SAMPLES;
         }
         buf += NELLY_BLOCK_LEN;
     }

     *got_frame_ptr   = 1;
     *(AVFrame *)data = s->frame;

     return buf_size;
 }

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

     av_freep(&s->float_buf);
     ff_mdct_end(&s->imdct_ctx);

     return 0;
 }

 AVCodec ff_nellymoser_decoder = {
     .name           = "nellymoser",
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = CODEC_ID_NELLYMOSER,
     .priv_data_size = sizeof(NellyMoserDecodeContext),
     .init           = decode_init,
     .close          = decode_end,
     .decode         = decode_tag,
     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
     .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
                                                       AV_SAMPLE_FMT_S16,
                                                       AV_SAMPLE_FMT_NONE },
 };
	/*
	* 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
	* 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 "libavutil/audioconvert.h"
	#include "avcodec.h"
	#include "dsputil.h"
	#include "fft.h"
	#include "fmtconvert.h"
	#include "sinewin.h"

	#define BITSTREAM_READER_LE
	#include "get_bits.h"


	typedef struct NellyMoserDecodeContext {
	AVCodecContext* avctx;
	AVFrame frame;
	float *float_buf;
	DECLARE_ALIGNED(16, float, state)[NELLY_BUF_LEN];
	AVLFG random_state;
	GetBitContext gb;
	float scale_bias;
	DSPContext dsp;
	FFTContext imdct_ctx;
	FmtConvertContext fmt_conv;
	DECLARE_ALIGNED(32, float, imdct_out)[NELLY_BUF_LEN * 2];
	} NellyMoserDecodeContext;

	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_long(&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));

	s->imdct_ctx.imdct_calc(&s->imdct_ctx, s->imdct_out, aptr);
	/* XXX: overlapping and windowing should be part of a more
	generic imdct function */
	s->dsp.vector_fmul_reverse(s->state, s->state, ff_sine_128, NELLY_BUF_LEN);
	s->dsp.vector_fmul_add(aptr, s->imdct_out, ff_sine_128, s->state, NELLY_BUF_LEN);
	memcpy(s->state, s->imdct_out + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
	}
	}

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

	s->avctx = avctx;
	av_lfg_init(&s->random_state, 0);
	ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);

	dsputil_init(&s->dsp, avctx);

	if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
	s->scale_bias = 1.0/(32768*8);
	avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
	} else {
	s->scale_bias = 1.0/(1*8);
	avctx->sample_fmt = AV_SAMPLE_FMT_S16;
	ff_fmt_convert_init(&s->fmt_conv, avctx);
	s->float_buf = av_mallocz(NELLY_SAMPLES * sizeof(*s->float_buf));
	if (!s->float_buf) {
	av_log(avctx, AV_LOG_ERROR, "error allocating float buffer\n");
	return AVERROR(ENOMEM);
	}
	}

	/* Generate overlap window */
	if (!ff_sine_128[127])
	ff_init_ff_sine_windows(7);

	avctx->channel_layout = AV_CH_LAYOUT_MONO;

	avcodec_get_frame_defaults(&s->frame);
	avctx->coded_frame = &s->frame;

	return 0;
	}

	static int decode_tag(AVCodecContext avctx, void data,
	int got_frame_ptr, AVPacket avpkt)
	{
	const uint8_t *buf = avpkt->data;
	const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
	int buf_size = avpkt->size;
	NellyMoserDecodeContext *s = avctx->priv_data;
	int blocks, i, ret;
	int16_t *samples_s16;
	float *samples_flt;

	blocks = buf_size / NELLY_BLOCK_LEN;

	if (blocks <= 0) {
	av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
	return AVERROR_INVALIDDATA;
	}

	if (buf_size % NELLY_BLOCK_LEN) {
	av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
	buf_size % NELLY_BLOCK_LEN);
	}
	/* Normal numbers of blocks for sample rates:
	* 8000 Hz - 1
	* 11025 Hz - 2
	* 16000 Hz - 3
	* 22050 Hz - 4
	* 44100 Hz - 8
	*/
	if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
	avctx->sample_rate= 11025*(blocks/2);

	/* get output buffer */
	s->frame.nb_samples = NELLY_SAMPLES * blocks;
	if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
	av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
	return ret;
	}
	samples_s16 = (int16_t *)s->frame.data[0];
	samples_flt = (float *)s->frame.data[0];

	for (i=0 ; i<blocks ; i++) {
	if (avctx->sample_fmt == AV_SAMPLE_FMT_FLT) {
	nelly_decode_block(s, buf, samples_flt);
	samples_flt += NELLY_SAMPLES;
	} else {
	nelly_decode_block(s, buf, s->float_buf);
	s->fmt_conv.float_to_int16(samples_s16, s->float_buf, NELLY_SAMPLES);
	samples_s16 += NELLY_SAMPLES;
	}
	buf += NELLY_BLOCK_LEN;
	}

	*got_frame_ptr = 1;
	(AVFrame )data = s->frame;

	return buf_size;
	}

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

	av_freep(&s->float_buf);
	ff_mdct_end(&s->imdct_ctx);

	return 0;
	}

	AVCodec ff_nellymoser_decoder = {
	.name = "nellymoser",
	.type = AVMEDIA_TYPE_AUDIO,
	.id = CODEC_ID_NELLYMOSER,
	.priv_data_size = sizeof(NellyMoserDecodeContext),
	.init = decode_init,
	.close = decode_end,
	.decode = decode_tag,
	.capabilities = CODEC_CAP_DR1 \| CODEC_CAP_PARAM_CHANGE,
	.long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
	.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
	AV_SAMPLE_FMT_S16,
	AV_SAMPLE_FMT_NONE },
	};