+++ /dev/null
-/*
- * 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) << 4;
- seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
- switch (seg) {
- case 0:
- t += 8;
- break;
- case 1:
- t += 0x108;
- break;
- default:
- t += 0x108;
- t <<= seg - 1;
- }
- 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
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