3 * Copyright (c) 2001 Fabrice Bellard.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27 /* from g711.c by SUN microsystems (unrestricted use) */
29 #define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */
30 #define QUANT_MASK (0xf) /* Quantization field mask. */
31 #define NSEGS (8) /* Number of A-law segments. */
32 #define SEG_SHIFT (4) /* Left shift for segment number. */
33 #define SEG_MASK (0x70) /* Segment field mask. */
35 #define BIAS (0x84) /* Bias for linear code. */
38 * alaw2linear() - Convert an A-law value to 16-bit linear PCM
41 static int alaw2linear(unsigned char a_val)
48 t = a_val & QUANT_MASK;
49 seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
50 if(seg) t= (t + t + 1 + 32) << (seg + 2);
51 else t= (t + t + 1 ) << 3;
53 return ((a_val & SIGN_BIT) ? t : -t);
56 static int ulaw2linear(unsigned char u_val)
60 /* Complement to obtain normal u-law value. */
64 * Extract and bias the quantization bits. Then
65 * shift up by the segment number and subtract out the bias.
67 t = ((u_val & QUANT_MASK) << 3) + BIAS;
68 t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
70 return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
73 /* 16384 entries per table */
74 static uint8_t *linear_to_alaw = NULL;
75 static int linear_to_alaw_ref = 0;
77 static uint8_t *linear_to_ulaw = NULL;
78 static int linear_to_ulaw_ref = 0;
80 static void build_xlaw_table(uint8_t *linear_to_xlaw,
81 int (*xlaw2linear)(unsigned char),
89 v1 = xlaw2linear(i ^ mask);
90 v2 = xlaw2linear((i + 1) ^ mask);
91 v = (v1 + v2 + 4) >> 3;
96 linear_to_xlaw[8192 + j] = (i ^ mask);
98 linear_to_xlaw[8192 - j] = (i ^ (mask ^ 0x80));
101 linear_to_xlaw[0] = linear_to_xlaw[1];
104 static int pcm_encode_init(AVCodecContext *avctx)
106 avctx->frame_size = 1;
107 switch(avctx->codec->id) {
108 case CODEC_ID_PCM_ALAW:
109 if (linear_to_alaw_ref == 0) {
110 linear_to_alaw = av_malloc(16384);
113 build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5);
115 linear_to_alaw_ref++;
117 case CODEC_ID_PCM_MULAW:
118 if (linear_to_ulaw_ref == 0) {
119 linear_to_ulaw = av_malloc(16384);
122 build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
124 linear_to_ulaw_ref++;
130 switch(avctx->codec->id) {
131 case CODEC_ID_PCM_S16LE:
132 case CODEC_ID_PCM_S16BE:
133 case CODEC_ID_PCM_U16LE:
134 case CODEC_ID_PCM_U16BE:
135 avctx->block_align = 2 * avctx->channels;
137 case CODEC_ID_PCM_S8:
138 case CODEC_ID_PCM_U8:
139 case CODEC_ID_PCM_MULAW:
140 case CODEC_ID_PCM_ALAW:
141 avctx->block_align = avctx->channels;
147 avctx->coded_frame= avcodec_alloc_frame();
148 avctx->coded_frame->key_frame= 1;
153 static int pcm_encode_close(AVCodecContext *avctx)
155 av_freep(&avctx->coded_frame);
157 switch(avctx->codec->id) {
158 case CODEC_ID_PCM_ALAW:
159 if (--linear_to_alaw_ref == 0)
160 av_free(linear_to_alaw);
162 case CODEC_ID_PCM_MULAW:
163 if (--linear_to_ulaw_ref == 0)
164 av_free(linear_to_ulaw);
167 /* nothing to free */
173 static int pcm_encode_frame(AVCodecContext *avctx,
174 unsigned char *frame, int buf_size, void *data)
176 int n, sample_size, v;
180 switch(avctx->codec->id) {
181 case CODEC_ID_PCM_S16LE:
182 case CODEC_ID_PCM_S16BE:
183 case CODEC_ID_PCM_U16LE:
184 case CODEC_ID_PCM_U16BE:
191 n = buf_size / sample_size;
195 switch(avctx->codec->id) {
196 case CODEC_ID_PCM_S16LE:
204 case CODEC_ID_PCM_S16BE:
212 case CODEC_ID_PCM_U16LE:
221 case CODEC_ID_PCM_U16BE:
230 case CODEC_ID_PCM_S8:
237 case CODEC_ID_PCM_U8:
240 dst[0] = (v >> 8) + 128;
244 case CODEC_ID_PCM_ALAW:
247 dst[0] = linear_to_alaw[(v + 32768) >> 2];
251 case CODEC_ID_PCM_MULAW:
254 dst[0] = linear_to_ulaw[(v + 32768) >> 2];
261 //avctx->frame_size = (dst - frame) / (sample_size * avctx->channels);
266 typedef struct PCMDecode {
270 static int pcm_decode_init(AVCodecContext * avctx)
272 PCMDecode *s = avctx->priv_data;
275 switch(avctx->codec->id) {
276 case CODEC_ID_PCM_ALAW:
278 s->table[i] = alaw2linear(i);
280 case CODEC_ID_PCM_MULAW:
282 s->table[i] = ulaw2linear(i);
290 static int pcm_decode_frame(AVCodecContext *avctx,
291 void *data, int *data_size,
292 uint8_t *buf, int buf_size)
294 PCMDecode *s = avctx->priv_data;
302 if(buf_size > AVCODEC_MAX_AUDIO_FRAME_SIZE/2)
303 buf_size = AVCODEC_MAX_AUDIO_FRAME_SIZE/2;
305 switch(avctx->codec->id) {
306 case CODEC_ID_PCM_S16LE:
309 *samples++ = src[0] | (src[1] << 8);
313 case CODEC_ID_PCM_S16BE:
316 *samples++ = (src[0] << 8) | src[1];
320 case CODEC_ID_PCM_U16LE:
323 *samples++ = (src[0] | (src[1] << 8)) - 0x8000;
327 case CODEC_ID_PCM_U16BE:
330 *samples++ = ((src[0] << 8) | src[1]) - 0x8000;
334 case CODEC_ID_PCM_S8:
337 *samples++ = src[0] << 8;
341 case CODEC_ID_PCM_U8:
344 *samples++ = ((int)src[0] - 128) << 8;
348 case CODEC_ID_PCM_ALAW:
349 case CODEC_ID_PCM_MULAW:
352 *samples++ = s->table[src[0]];
359 *data_size = (uint8_t *)samples - (uint8_t *)data;
363 #define PCM_CODEC(id, name) \
364 AVCodec name ## _encoder = { \
374 AVCodec name ## _decoder = { \
385 PCM_CODEC(CODEC_ID_PCM_S16LE, pcm_s16le);
386 PCM_CODEC(CODEC_ID_PCM_S16BE, pcm_s16be);
387 PCM_CODEC(CODEC_ID_PCM_U16LE, pcm_u16le);
388 PCM_CODEC(CODEC_ID_PCM_U16BE, pcm_u16be);
389 PCM_CODEC(CODEC_ID_PCM_S8, pcm_s8);
390 PCM_CODEC(CODEC_ID_PCM_U8, pcm_u8);
391 PCM_CODEC(CODEC_ID_PCM_ALAW, pcm_alaw);
392 PCM_CODEC(CODEC_ID_PCM_MULAW, pcm_mulaw);