libavcodec/8svx.c - third_party/ffmpeg - Git at Google

 /*
  * Copyright (C) 2008 Jaikrishnan Menon
  * Copyright (C) 2011 Stefano Sabatini
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */

 /**
  * @file
  * 8svx audio decoder
  * supports: fibonacci delta encoding
  *         : exponential encoding
  *
  * For more information about the 8SVX format:
  * http://netghost.narod.ru/gff/vendspec/iff/iff.txt
  * http://sox.sourceforge.net/AudioFormats-11.html
  * http://aminet.net/package/mus/misc/wavepak
  * http://amigan.1emu.net/reg/8SVX.txt
  *
  * Samples can be found here:
  * http://aminet.net/mods/smpl/
  */

 #include "avcodec.h"

 /** decoder context */
 typedef struct EightSvxContext {
     const int8_t *table;

     /* buffer used to store the whole audio decoded/interleaved chunk,
      * which is sent with the first packet */
     uint8_t *samples;
     size_t samples_size;
     int samples_idx;
 } EightSvxContext;

 static const int8_t fibonacci[16]   = { -34,  -21, -13,  -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8,  13, 21 };
 static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0, 1, 2, 4, 8, 16, 32, 64 };

 #define MAX_FRAME_SIZE 2048

 /**
  * Interleave samples in buffer containing all left channel samples
  * at the beginning, and right channel samples at the end.
  * Each sample is assumed to be in signed 8-bit format.
  *
  * @param size the size in bytes of the dst and src buffer
  */
 static void interleave_stereo(uint8_t *dst, const uint8_t *src, int size)
 {
     uint8_t *dst_end = dst + size;
     size = size>>1;

     while (dst < dst_end) {
         *dst++ = *src;
         *dst++ = *(src+size);
         src++;
     }
 }

 /**
  * Delta decode the compressed values in src, and put the resulting
  * decoded n samples in dst.
  *
  * @param val starting value assumed by the delta sequence
  * @param table delta sequence table
  * @return size in bytes of the decoded data, must be src_size*2
  */
 static int delta_decode(int8_t *dst, const uint8_t *src, int src_size,
                         int8_t val, const int8_t *table)
 {
     int n = src_size;
     int8_t *dst0 = dst;

     while (n--) {
         uint8_t d = *src++;
         val = av_clip(val + table[d & 0x0f], -127, 128);
         *dst++ = val;
         val = av_clip(val + table[d >> 4]  , -127, 128);
         *dst++ = val;
     }

     return dst-dst0;
 }

 static int eightsvx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
                                  AVPacket *avpkt)
 {
     EightSvxContext *esc = avctx->priv_data;
     int out_data_size, n;
     uint8_t *src, *dst;

     /* decode and interleave the first packet */
     if (!esc->samples && avpkt) {
         uint8_t *deinterleaved_samples;

         esc->samples_size = avctx->codec->id == CODEC_ID_8SVX_RAW ?
             avpkt->size : avctx->channels + (avpkt->size-avctx->channels) * 2;
         if (!(esc->samples = av_malloc(esc->samples_size)))
             return AVERROR(ENOMEM);

         /* decompress */
         if (avctx->codec->id == CODEC_ID_8SVX_FIB || avctx->codec->id == CODEC_ID_8SVX_EXP) {
             const uint8_t *buf = avpkt->data;
             int buf_size = avpkt->size;
             int n = esc->samples_size;

             if (!(deinterleaved_samples = av_mallocz(n)))
                 return AVERROR(ENOMEM);

             /* the uncompressed starting value is contained in the first byte */
             if (avctx->channels == 2) {
                 delta_decode(deinterleaved_samples      , buf+1, buf_size/2-1, buf[0], esc->table);
                 buf += buf_size/2;
                 delta_decode(deinterleaved_samples+n/2-1, buf+1, buf_size/2-1, buf[0], esc->table);
             } else
                 delta_decode(deinterleaved_samples      , buf+1, buf_size-1  , buf[0], esc->table);
         } else {
             deinterleaved_samples = avpkt->data;
         }

         if (avctx->channels == 2)
             interleave_stereo(esc->samples, deinterleaved_samples, esc->samples_size);
         else
             memcpy(esc->samples, deinterleaved_samples, esc->samples_size);
     }

     /* return single packed with fixed size */
     out_data_size = FFMIN(MAX_FRAME_SIZE, esc->samples_size - esc->samples_idx);
     if (*data_size < out_data_size) {
         av_log(avctx, AV_LOG_ERROR, "Provided buffer with size %d is too small.\n", *data_size);
         return AVERROR(EINVAL);
     }

     *data_size = out_data_size;
     dst = data;
     src = esc->samples + esc->samples_idx;
     for (n = out_data_size; n > 0; n--)
         *dst++ = *src++ + 128;
     esc->samples_idx += *data_size;

     return avctx->codec->id == CODEC_ID_8SVX_FIB || avctx->codec->id == CODEC_ID_8SVX_EXP ?
         (avctx->frame_number == 0)*2 + out_data_size / 2 :
         out_data_size;
 }

 static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
 {
     EightSvxContext *esc = avctx->priv_data;

     if (avctx->channels > 2) {
         av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n");
         return AVERROR_INVALIDDATA;
     }

     switch (avctx->codec->id) {
     case CODEC_ID_8SVX_FIB: esc->table = fibonacci;    break;
     case CODEC_ID_8SVX_EXP: esc->table = exponential;  break;
     case CODEC_ID_8SVX_RAW: esc->table = NULL;         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Invalid codec id %d.\n", avctx->codec->id);
         return AVERROR_INVALIDDATA;
     }
     avctx->sample_fmt = AV_SAMPLE_FMT_U8;

     return 0;
 }

 static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
 {
     EightSvxContext *esc = avctx->priv_data;

     av_freep(&esc->samples);
     esc->samples_size = 0;
     esc->samples_idx = 0;

     return 0;
 }

 AVCodec ff_eightsvx_fib_decoder = {
   .name           = "8svx_fib",
   .type           = AVMEDIA_TYPE_AUDIO,
   .id             = CODEC_ID_8SVX_FIB,
   .priv_data_size = sizeof (EightSvxContext),
   .init           = eightsvx_decode_init,
   .decode         = eightsvx_decode_frame,
   .close          = eightsvx_decode_close,
   .long_name      = NULL_IF_CONFIG_SMALL("8SVX fibonacci"),
 };

 AVCodec ff_eightsvx_exp_decoder = {
   .name           = "8svx_exp",
   .type           = AVMEDIA_TYPE_AUDIO,
   .id             = CODEC_ID_8SVX_EXP,
   .priv_data_size = sizeof (EightSvxContext),
   .init           = eightsvx_decode_init,
   .decode         = eightsvx_decode_frame,
   .close          = eightsvx_decode_close,
   .long_name      = NULL_IF_CONFIG_SMALL("8SVX exponential"),
 };

 AVCodec ff_eightsvx_raw_decoder = {
   .name           = "8svx_raw",
   .type           = AVMEDIA_TYPE_AUDIO,
   .id             = CODEC_ID_8SVX_RAW,
   .priv_data_size = sizeof(EightSvxContext),
   .init           = eightsvx_decode_init,
   .decode         = eightsvx_decode_frame,
   .close          = eightsvx_decode_close,
   .long_name      = NULL_IF_CONFIG_SMALL("8SVX rawaudio"),
 };
	/*
	* Copyright (C) 2008 Jaikrishnan Menon
	* Copyright (C) 2011 Stefano Sabatini
	*
	* This file is part of FFmpeg.
	*
	* FFmpeg is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* FFmpeg is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with FFmpeg; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	/**
	* @file
	* 8svx audio decoder
	* supports: fibonacci delta encoding
	* : exponential encoding
	*
	* For more information about the 8SVX format:
	* http://netghost.narod.ru/gff/vendspec/iff/iff.txt
	* http://sox.sourceforge.net/AudioFormats-11.html
	* http://aminet.net/package/mus/misc/wavepak
	* http://amigan.1emu.net/reg/8SVX.txt
	*
	* Samples can be found here:
	* http://aminet.net/mods/smpl/
	*/

	#include "avcodec.h"

	/** decoder context */
	typedef struct EightSvxContext {
	const int8_t *table;

	/* buffer used to store the whole audio decoded/interleaved chunk,
	* which is sent with the first packet */
	uint8_t *samples;
	size_t samples_size;
	int samples_idx;
	} EightSvxContext;

	static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8, 13, 21 };
	static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0, 1, 2, 4, 8, 16, 32, 64 };

	#define MAX_FRAME_SIZE 2048

	/**
	* Interleave samples in buffer containing all left channel samples
	* at the beginning, and right channel samples at the end.
	* Each sample is assumed to be in signed 8-bit format.
	*
	* @param size the size in bytes of the dst and src buffer
	*/
	static void interleave_stereo(uint8_t dst, const uint8_t src, int size)
	{
	uint8_t *dst_end = dst + size;
	size = size>>1;

	while (dst < dst_end) {
	dst++ = src;
	dst++ = (src+size);
	src++;
	}
	}

	/**
	* Delta decode the compressed values in src, and put the resulting
	* decoded n samples in dst.
	*
	* @param val starting value assumed by the delta sequence
	* @param table delta sequence table
	* @return size in bytes of the decoded data, must be src_size*2
	*/
	static int delta_decode(int8_t dst, const uint8_t src, int src_size,
	int8_t val, const int8_t *table)
	{
	int n = src_size;
	int8_t *dst0 = dst;

	while (n--) {
	uint8_t d = *src++;
	val = av_clip(val + table[d & 0x0f], -127, 128);
	*dst++ = val;
	val = av_clip(val + table[d >> 4] , -127, 128);
	*dst++ = val;
	}

	return dst-dst0;
	}

	static int eightsvx_decode_frame(AVCodecContext avctx, void data, int *data_size,
	AVPacket *avpkt)
	{
	EightSvxContext *esc = avctx->priv_data;
	int out_data_size, n;
	uint8_t src, dst;

	/* decode and interleave the first packet */
	if (!esc->samples && avpkt) {
	uint8_t *deinterleaved_samples;

	esc->samples_size = avctx->codec->id == CODEC_ID_8SVX_RAW ?
	avpkt->size : avctx->channels + (avpkt->size-avctx->channels) * 2;
	if (!(esc->samples = av_malloc(esc->samples_size)))
	return AVERROR(ENOMEM);

	/* decompress */
	if (avctx->codec->id == CODEC_ID_8SVX_FIB \|\| avctx->codec->id == CODEC_ID_8SVX_EXP) {
	const uint8_t *buf = avpkt->data;
	int buf_size = avpkt->size;
	int n = esc->samples_size;

	if (!(deinterleaved_samples = av_mallocz(n)))
	return AVERROR(ENOMEM);

	/* the uncompressed starting value is contained in the first byte */
	if (avctx->channels == 2) {
	delta_decode(deinterleaved_samples , buf+1, buf_size/2-1, buf[0], esc->table);
	buf += buf_size/2;
	delta_decode(deinterleaved_samples+n/2-1, buf+1, buf_size/2-1, buf[0], esc->table);
	} else
	delta_decode(deinterleaved_samples , buf+1, buf_size-1 , buf[0], esc->table);
	} else {
	deinterleaved_samples = avpkt->data;
	}

	if (avctx->channels == 2)
	interleave_stereo(esc->samples, deinterleaved_samples, esc->samples_size);
	else
	memcpy(esc->samples, deinterleaved_samples, esc->samples_size);
	}

	/* return single packed with fixed size */
	out_data_size = FFMIN(MAX_FRAME_SIZE, esc->samples_size - esc->samples_idx);
	if (*data_size < out_data_size) {
	av_log(avctx, AV_LOG_ERROR, "Provided buffer with size %d is too small.\n", *data_size);
	return AVERROR(EINVAL);
	}

	*data_size = out_data_size;
	dst = data;
	src = esc->samples + esc->samples_idx;
	for (n = out_data_size; n > 0; n--)
	dst++ = src++ + 128;
	esc->samples_idx += *data_size;

	return avctx->codec->id == CODEC_ID_8SVX_FIB \|\| avctx->codec->id == CODEC_ID_8SVX_EXP ?
	(avctx->frame_number == 0)*2 + out_data_size / 2 :
	out_data_size;
	}

	static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
	{
	EightSvxContext *esc = avctx->priv_data;

	if (avctx->channels > 2) {
	av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n");
	return AVERROR_INVALIDDATA;
	}

	switch (avctx->codec->id) {
	case CODEC_ID_8SVX_FIB: esc->table = fibonacci; break;
	case CODEC_ID_8SVX_EXP: esc->table = exponential; break;
	case CODEC_ID_8SVX_RAW: esc->table = NULL; break;
	default:
	av_log(avctx, AV_LOG_ERROR, "Invalid codec id %d.\n", avctx->codec->id);
	return AVERROR_INVALIDDATA;
	}
	avctx->sample_fmt = AV_SAMPLE_FMT_U8;

	return 0;
	}

	static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
	{
	EightSvxContext *esc = avctx->priv_data;

	av_freep(&esc->samples);
	esc->samples_size = 0;
	esc->samples_idx = 0;

	return 0;
	}

	AVCodec ff_eightsvx_fib_decoder = {
	.name = "8svx_fib",
	.type = AVMEDIA_TYPE_AUDIO,
	.id = CODEC_ID_8SVX_FIB,
	.priv_data_size = sizeof (EightSvxContext),
	.init = eightsvx_decode_init,
	.decode = eightsvx_decode_frame,
	.close = eightsvx_decode_close,
	.long_name = NULL_IF_CONFIG_SMALL("8SVX fibonacci"),
	};

	AVCodec ff_eightsvx_exp_decoder = {
	.name = "8svx_exp",
	.type = AVMEDIA_TYPE_AUDIO,
	.id = CODEC_ID_8SVX_EXP,
	.priv_data_size = sizeof (EightSvxContext),
	.init = eightsvx_decode_init,
	.decode = eightsvx_decode_frame,
	.close = eightsvx_decode_close,
	.long_name = NULL_IF_CONFIG_SMALL("8SVX exponential"),
	};

	AVCodec ff_eightsvx_raw_decoder = {
	.name = "8svx_raw",
	.type = AVMEDIA_TYPE_AUDIO,
	.id = CODEC_ID_8SVX_RAW,
	.priv_data_size = sizeof(EightSvxContext),
	.init = eightsvx_decode_init,
	.decode = eightsvx_decode_frame,
	.close = eightsvx_decode_close,
	.long_name = NULL_IF_CONFIG_SMALL("8SVX rawaudio"),
	};