mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-23 12:43:46 +02:00
376 lines
9.4 KiB
C
376 lines
9.4 KiB
C
/*
|
|
* PCM codecs
|
|
* Copyright (c) 2001 Fabrice Bellard.
|
|
*
|
|
* This library 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 of the License, or (at your option) any later version.
|
|
*
|
|
* This library 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 this library; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
/**
|
|
* @file pcm.c
|
|
* PCM codecs
|
|
*/
|
|
|
|
#include "avcodec.h"
|
|
|
|
/* from g711.c by SUN microsystems (unrestricted use) */
|
|
|
|
#define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */
|
|
#define QUANT_MASK (0xf) /* Quantization field mask. */
|
|
#define NSEGS (8) /* Number of A-law segments. */
|
|
#define SEG_SHIFT (4) /* Left shift for segment number. */
|
|
#define SEG_MASK (0x70) /* Segment field mask. */
|
|
|
|
#define BIAS (0x84) /* Bias for linear code. */
|
|
|
|
/*
|
|
* alaw2linear() - Convert an A-law value to 16-bit linear PCM
|
|
*
|
|
*/
|
|
static int alaw2linear(unsigned char a_val)
|
|
{
|
|
int t;
|
|
int seg;
|
|
|
|
a_val ^= 0x55;
|
|
|
|
t = a_val & QUANT_MASK;
|
|
seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
|
|
if(seg) t= (t + t + 1 + 32) << (seg + 2);
|
|
else t= (t + t + 1 ) << 3;
|
|
|
|
return ((a_val & SIGN_BIT) ? t : -t);
|
|
}
|
|
|
|
static int ulaw2linear(unsigned char u_val)
|
|
{
|
|
int t;
|
|
|
|
/* Complement to obtain normal u-law value. */
|
|
u_val = ~u_val;
|
|
|
|
/*
|
|
* Extract and bias the quantization bits. Then
|
|
* shift up by the segment number and subtract out the bias.
|
|
*/
|
|
t = ((u_val & QUANT_MASK) << 3) + BIAS;
|
|
t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
|
|
|
|
return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
|
|
}
|
|
|
|
/* 16384 entries per table */
|
|
static uint8_t *linear_to_alaw = NULL;
|
|
static int linear_to_alaw_ref = 0;
|
|
|
|
static uint8_t *linear_to_ulaw = NULL;
|
|
static int linear_to_ulaw_ref = 0;
|
|
|
|
static void build_xlaw_table(uint8_t *linear_to_xlaw,
|
|
int (*xlaw2linear)(unsigned char),
|
|
int mask)
|
|
{
|
|
int i, j, v, v1, v2;
|
|
|
|
j = 0;
|
|
for(i=0;i<128;i++) {
|
|
if (i != 127) {
|
|
v1 = xlaw2linear(i ^ mask);
|
|
v2 = xlaw2linear((i + 1) ^ mask);
|
|
v = (v1 + v2 + 4) >> 3;
|
|
} else {
|
|
v = 8192;
|
|
}
|
|
for(;j<v;j++) {
|
|
linear_to_xlaw[8192 + j] = (i ^ mask);
|
|
if (j > 0)
|
|
linear_to_xlaw[8192 - j] = (i ^ (mask ^ 0x80));
|
|
}
|
|
}
|
|
linear_to_xlaw[0] = linear_to_xlaw[1];
|
|
}
|
|
|
|
static int pcm_encode_init(AVCodecContext *avctx)
|
|
{
|
|
avctx->frame_size = 1;
|
|
switch(avctx->codec->id) {
|
|
case CODEC_ID_PCM_ALAW:
|
|
if (linear_to_alaw_ref == 0) {
|
|
linear_to_alaw = av_malloc(16384);
|
|
if (!linear_to_alaw)
|
|
return -1;
|
|
build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5);
|
|
}
|
|
linear_to_alaw_ref++;
|
|
break;
|
|
case CODEC_ID_PCM_MULAW:
|
|
if (linear_to_ulaw_ref == 0) {
|
|
linear_to_ulaw = av_malloc(16384);
|
|
if (!linear_to_ulaw)
|
|
return -1;
|
|
build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
|
|
}
|
|
linear_to_ulaw_ref++;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
avctx->coded_frame= avcodec_alloc_frame();
|
|
avctx->coded_frame->key_frame= 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pcm_encode_close(AVCodecContext *avctx)
|
|
{
|
|
av_freep(&avctx->coded_frame);
|
|
|
|
switch(avctx->codec->id) {
|
|
case CODEC_ID_PCM_ALAW:
|
|
if (--linear_to_alaw_ref == 0)
|
|
av_free(linear_to_alaw);
|
|
break;
|
|
case CODEC_ID_PCM_MULAW:
|
|
if (--linear_to_ulaw_ref == 0)
|
|
av_free(linear_to_ulaw);
|
|
break;
|
|
default:
|
|
/* nothing to free */
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int pcm_encode_frame(AVCodecContext *avctx,
|
|
unsigned char *frame, int buf_size, void *data)
|
|
{
|
|
int n, sample_size, v;
|
|
short *samples;
|
|
unsigned char *dst;
|
|
|
|
switch(avctx->codec->id) {
|
|
case CODEC_ID_PCM_S16LE:
|
|
case CODEC_ID_PCM_S16BE:
|
|
case CODEC_ID_PCM_U16LE:
|
|
case CODEC_ID_PCM_U16BE:
|
|
sample_size = 2;
|
|
break;
|
|
default:
|
|
sample_size = 1;
|
|
break;
|
|
}
|
|
n = buf_size / sample_size;
|
|
samples = data;
|
|
dst = frame;
|
|
|
|
switch(avctx->codec->id) {
|
|
case CODEC_ID_PCM_S16LE:
|
|
for(;n>0;n--) {
|
|
v = *samples++;
|
|
dst[0] = v & 0xff;
|
|
dst[1] = v >> 8;
|
|
dst += 2;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_S16BE:
|
|
for(;n>0;n--) {
|
|
v = *samples++;
|
|
dst[0] = v >> 8;
|
|
dst[1] = v;
|
|
dst += 2;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_U16LE:
|
|
for(;n>0;n--) {
|
|
v = *samples++;
|
|
v += 0x8000;
|
|
dst[0] = v & 0xff;
|
|
dst[1] = v >> 8;
|
|
dst += 2;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_U16BE:
|
|
for(;n>0;n--) {
|
|
v = *samples++;
|
|
v += 0x8000;
|
|
dst[0] = v >> 8;
|
|
dst[1] = v;
|
|
dst += 2;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_S8:
|
|
for(;n>0;n--) {
|
|
v = *samples++;
|
|
dst[0] = v >> 8;
|
|
dst++;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_U8:
|
|
for(;n>0;n--) {
|
|
v = *samples++;
|
|
dst[0] = (v >> 8) + 128;
|
|
dst++;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_ALAW:
|
|
for(;n>0;n--) {
|
|
v = *samples++;
|
|
dst[0] = linear_to_alaw[(v + 32768) >> 2];
|
|
dst++;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_MULAW:
|
|
for(;n>0;n--) {
|
|
v = *samples++;
|
|
dst[0] = linear_to_ulaw[(v + 32768) >> 2];
|
|
dst++;
|
|
}
|
|
break;
|
|
default:
|
|
return -1;
|
|
}
|
|
//avctx->frame_size = (dst - frame) / (sample_size * avctx->channels);
|
|
|
|
return dst - frame;
|
|
}
|
|
|
|
typedef struct PCMDecode {
|
|
short table[256];
|
|
} PCMDecode;
|
|
|
|
static int pcm_decode_init(AVCodecContext * avctx)
|
|
{
|
|
PCMDecode *s = avctx->priv_data;
|
|
int i;
|
|
|
|
switch(avctx->codec->id) {
|
|
case CODEC_ID_PCM_ALAW:
|
|
for(i=0;i<256;i++)
|
|
s->table[i] = alaw2linear(i);
|
|
break;
|
|
case CODEC_ID_PCM_MULAW:
|
|
for(i=0;i<256;i++)
|
|
s->table[i] = ulaw2linear(i);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int pcm_decode_frame(AVCodecContext *avctx,
|
|
void *data, int *data_size,
|
|
uint8_t *buf, int buf_size)
|
|
{
|
|
PCMDecode *s = avctx->priv_data;
|
|
int n;
|
|
short *samples;
|
|
uint8_t *src;
|
|
|
|
samples = data;
|
|
src = buf;
|
|
|
|
switch(avctx->codec->id) {
|
|
case CODEC_ID_PCM_S16LE:
|
|
n = buf_size >> 1;
|
|
for(;n>0;n--) {
|
|
*samples++ = src[0] | (src[1] << 8);
|
|
src += 2;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_S16BE:
|
|
n = buf_size >> 1;
|
|
for(;n>0;n--) {
|
|
*samples++ = (src[0] << 8) | src[1];
|
|
src += 2;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_U16LE:
|
|
n = buf_size >> 1;
|
|
for(;n>0;n--) {
|
|
*samples++ = (src[0] | (src[1] << 8)) - 0x8000;
|
|
src += 2;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_U16BE:
|
|
n = buf_size >> 1;
|
|
for(;n>0;n--) {
|
|
*samples++ = ((src[0] << 8) | src[1]) - 0x8000;
|
|
src += 2;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_S8:
|
|
n = buf_size;
|
|
for(;n>0;n--) {
|
|
*samples++ = src[0] << 8;
|
|
src++;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_U8:
|
|
n = buf_size;
|
|
for(;n>0;n--) {
|
|
*samples++ = ((int)src[0] - 128) << 8;
|
|
src++;
|
|
}
|
|
break;
|
|
case CODEC_ID_PCM_ALAW:
|
|
case CODEC_ID_PCM_MULAW:
|
|
n = buf_size;
|
|
for(;n>0;n--) {
|
|
*samples++ = s->table[src[0]];
|
|
src++;
|
|
}
|
|
break;
|
|
default:
|
|
*data_size = 0;
|
|
return -1;
|
|
}
|
|
*data_size = (uint8_t *)samples - (uint8_t *)data;
|
|
return src - buf;
|
|
}
|
|
|
|
#define PCM_CODEC(id, name) \
|
|
AVCodec name ## _encoder = { \
|
|
#name, \
|
|
CODEC_TYPE_AUDIO, \
|
|
id, \
|
|
0, \
|
|
pcm_encode_init, \
|
|
pcm_encode_frame, \
|
|
pcm_encode_close, \
|
|
NULL, \
|
|
}; \
|
|
AVCodec name ## _decoder = { \
|
|
#name, \
|
|
CODEC_TYPE_AUDIO, \
|
|
id, \
|
|
sizeof(PCMDecode), \
|
|
pcm_decode_init, \
|
|
NULL, \
|
|
NULL, \
|
|
pcm_decode_frame, \
|
|
}
|
|
|
|
PCM_CODEC(CODEC_ID_PCM_S16LE, pcm_s16le);
|
|
PCM_CODEC(CODEC_ID_PCM_S16BE, pcm_s16be);
|
|
PCM_CODEC(CODEC_ID_PCM_U16LE, pcm_u16le);
|
|
PCM_CODEC(CODEC_ID_PCM_U16BE, pcm_u16be);
|
|
PCM_CODEC(CODEC_ID_PCM_S8, pcm_s8);
|
|
PCM_CODEC(CODEC_ID_PCM_U8, pcm_u8);
|
|
PCM_CODEC(CODEC_ID_PCM_ALAW, pcm_alaw);
|
|
PCM_CODEC(CODEC_ID_PCM_MULAW, pcm_mulaw);
|
|
|
|
#undef PCM_CODEC
|