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546 lines
15 KiB
546 lines
15 KiB
/* |
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* PCM codecs |
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* Copyright (c) 2001 Fabrice Bellard. |
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* |
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* This library is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2 of the License, or (at your option) any later version. |
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* |
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* This library is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with this library; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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|
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/** |
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* @file pcm.c |
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* PCM codecs |
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*/ |
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#include "avcodec.h" |
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#include "bitstream.h" // for ff_reverse |
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|
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/* from g711.c by SUN microsystems (unrestricted use) */ |
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#define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */ |
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#define QUANT_MASK (0xf) /* Quantization field mask. */ |
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#define NSEGS (8) /* Number of A-law segments. */ |
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#define SEG_SHIFT (4) /* Left shift for segment number. */ |
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#define SEG_MASK (0x70) /* Segment field mask. */ |
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#define BIAS (0x84) /* Bias for linear code. */ |
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|
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/* |
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* alaw2linear() - Convert an A-law value to 16-bit linear PCM |
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* |
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*/ |
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static int alaw2linear(unsigned char a_val) |
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{ |
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int t; |
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int seg; |
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a_val ^= 0x55; |
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t = a_val & QUANT_MASK; |
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seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT; |
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if(seg) t= (t + t + 1 + 32) << (seg + 2); |
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else t= (t + t + 1 ) << 3; |
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return ((a_val & SIGN_BIT) ? t : -t); |
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} |
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static int ulaw2linear(unsigned char u_val) |
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{ |
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int t; |
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/* Complement to obtain normal u-law value. */ |
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u_val = ~u_val; |
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/* |
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* Extract and bias the quantization bits. Then |
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* shift up by the segment number and subtract out the bias. |
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*/ |
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t = ((u_val & QUANT_MASK) << 3) + BIAS; |
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t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT; |
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return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS)); |
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} |
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/* 16384 entries per table */ |
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static uint8_t *linear_to_alaw = NULL; |
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static int linear_to_alaw_ref = 0; |
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static uint8_t *linear_to_ulaw = NULL; |
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static int linear_to_ulaw_ref = 0; |
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static void build_xlaw_table(uint8_t *linear_to_xlaw, |
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int (*xlaw2linear)(unsigned char), |
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int mask) |
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{ |
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int i, j, v, v1, v2; |
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j = 0; |
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for(i=0;i<128;i++) { |
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if (i != 127) { |
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v1 = xlaw2linear(i ^ mask); |
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v2 = xlaw2linear((i + 1) ^ mask); |
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v = (v1 + v2 + 4) >> 3; |
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} else { |
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v = 8192; |
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} |
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for(;j<v;j++) { |
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linear_to_xlaw[8192 + j] = (i ^ mask); |
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if (j > 0) |
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linear_to_xlaw[8192 - j] = (i ^ (mask ^ 0x80)); |
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} |
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} |
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linear_to_xlaw[0] = linear_to_xlaw[1]; |
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} |
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static int pcm_encode_init(AVCodecContext *avctx) |
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{ |
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avctx->frame_size = 1; |
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switch(avctx->codec->id) { |
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case CODEC_ID_PCM_ALAW: |
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if (linear_to_alaw_ref == 0) { |
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linear_to_alaw = av_malloc(16384); |
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if (!linear_to_alaw) |
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return -1; |
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build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5); |
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} |
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linear_to_alaw_ref++; |
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break; |
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case CODEC_ID_PCM_MULAW: |
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if (linear_to_ulaw_ref == 0) { |
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linear_to_ulaw = av_malloc(16384); |
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if (!linear_to_ulaw) |
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return -1; |
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build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff); |
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} |
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linear_to_ulaw_ref++; |
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break; |
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default: |
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break; |
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} |
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switch(avctx->codec->id) { |
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case CODEC_ID_PCM_S32LE: |
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case CODEC_ID_PCM_S32BE: |
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case CODEC_ID_PCM_U32LE: |
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case CODEC_ID_PCM_U32BE: |
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avctx->block_align = 4 * avctx->channels; |
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break; |
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case CODEC_ID_PCM_S24LE: |
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case CODEC_ID_PCM_S24BE: |
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case CODEC_ID_PCM_U24LE: |
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case CODEC_ID_PCM_U24BE: |
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case CODEC_ID_PCM_S24DAUD: |
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avctx->block_align = 3 * avctx->channels; |
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break; |
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case CODEC_ID_PCM_S16LE: |
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case CODEC_ID_PCM_S16BE: |
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case CODEC_ID_PCM_U16LE: |
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case CODEC_ID_PCM_U16BE: |
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avctx->block_align = 2 * avctx->channels; |
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break; |
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case CODEC_ID_PCM_S8: |
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case CODEC_ID_PCM_U8: |
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case CODEC_ID_PCM_MULAW: |
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case CODEC_ID_PCM_ALAW: |
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avctx->block_align = avctx->channels; |
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break; |
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default: |
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break; |
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} |
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avctx->coded_frame= avcodec_alloc_frame(); |
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avctx->coded_frame->key_frame= 1; |
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return 0; |
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} |
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static int pcm_encode_close(AVCodecContext *avctx) |
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{ |
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av_freep(&avctx->coded_frame); |
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switch(avctx->codec->id) { |
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case CODEC_ID_PCM_ALAW: |
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if (--linear_to_alaw_ref == 0) |
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av_free(linear_to_alaw); |
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break; |
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case CODEC_ID_PCM_MULAW: |
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if (--linear_to_ulaw_ref == 0) |
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av_free(linear_to_ulaw); |
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break; |
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default: |
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/* nothing to free */ |
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break; |
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} |
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return 0; |
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} |
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/** |
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* \brief convert samples from 16 bit |
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* \param bps byte per sample for the destination format, must be >= 2 |
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* \param le 0 for big-, 1 for little-endian |
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* \param us 0 for signed, 1 for unsigned output |
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* \param samples input samples |
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* \param dst output samples |
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* \param n number of samples in samples buffer. |
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*/ |
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static inline void encode_from16(int bps, int le, int us, |
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short **samples, uint8_t **dst, int n) { |
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if (bps > 2) |
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memset(*dst, 0, n * bps); |
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if (le) *dst += bps - 2; |
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for(;n>0;n--) { |
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register int v = *(*samples)++; |
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if (us) v += 0x8000; |
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(*dst)[le] = v >> 8; |
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(*dst)[1 - le] = v; |
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*dst += bps; |
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} |
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if (le) *dst -= bps - 2; |
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} |
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static int pcm_encode_frame(AVCodecContext *avctx, |
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unsigned char *frame, int buf_size, void *data) |
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{ |
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int n, sample_size, v; |
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short *samples; |
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unsigned char *dst; |
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switch(avctx->codec->id) { |
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case CODEC_ID_PCM_S32LE: |
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case CODEC_ID_PCM_S32BE: |
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case CODEC_ID_PCM_U32LE: |
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case CODEC_ID_PCM_U32BE: |
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sample_size = 4; |
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break; |
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case CODEC_ID_PCM_S24LE: |
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case CODEC_ID_PCM_S24BE: |
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case CODEC_ID_PCM_U24LE: |
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case CODEC_ID_PCM_U24BE: |
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case CODEC_ID_PCM_S24DAUD: |
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sample_size = 3; |
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break; |
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case CODEC_ID_PCM_S16LE: |
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case CODEC_ID_PCM_S16BE: |
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case CODEC_ID_PCM_U16LE: |
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case CODEC_ID_PCM_U16BE: |
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sample_size = 2; |
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break; |
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default: |
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sample_size = 1; |
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break; |
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} |
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n = buf_size / sample_size; |
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samples = data; |
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dst = frame; |
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switch(avctx->codec->id) { |
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case CODEC_ID_PCM_S32LE: |
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encode_from16(4, 1, 0, &samples, &dst, n); |
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break; |
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case CODEC_ID_PCM_S32BE: |
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encode_from16(4, 0, 0, &samples, &dst, n); |
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break; |
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case CODEC_ID_PCM_U32LE: |
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encode_from16(4, 1, 1, &samples, &dst, n); |
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break; |
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case CODEC_ID_PCM_U32BE: |
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encode_from16(4, 0, 1, &samples, &dst, n); |
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break; |
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case CODEC_ID_PCM_S24LE: |
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encode_from16(3, 1, 0, &samples, &dst, n); |
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break; |
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case CODEC_ID_PCM_S24BE: |
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encode_from16(3, 0, 0, &samples, &dst, n); |
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break; |
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case CODEC_ID_PCM_U24LE: |
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encode_from16(3, 1, 1, &samples, &dst, n); |
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break; |
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case CODEC_ID_PCM_U24BE: |
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encode_from16(3, 0, 1, &samples, &dst, n); |
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break; |
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case CODEC_ID_PCM_S24DAUD: |
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for(;n>0;n--) { |
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uint32_t tmp = ff_reverse[*samples >> 8] + |
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(ff_reverse[*samples & 0xff] << 8); |
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tmp <<= 4; // sync flags would go here |
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dst[2] = tmp & 0xff; |
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tmp >>= 8; |
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dst[1] = tmp & 0xff; |
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dst[0] = tmp >> 8; |
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samples++; |
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dst += 3; |
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} |
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break; |
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case CODEC_ID_PCM_S16LE: |
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for(;n>0;n--) { |
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v = *samples++; |
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dst[0] = v & 0xff; |
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dst[1] = v >> 8; |
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dst += 2; |
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} |
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break; |
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case CODEC_ID_PCM_S16BE: |
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for(;n>0;n--) { |
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v = *samples++; |
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dst[0] = v >> 8; |
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dst[1] = v; |
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dst += 2; |
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} |
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break; |
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case CODEC_ID_PCM_U16LE: |
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for(;n>0;n--) { |
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v = *samples++; |
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v += 0x8000; |
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dst[0] = v & 0xff; |
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dst[1] = v >> 8; |
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dst += 2; |
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} |
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break; |
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case CODEC_ID_PCM_U16BE: |
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for(;n>0;n--) { |
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v = *samples++; |
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v += 0x8000; |
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dst[0] = v >> 8; |
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dst[1] = v; |
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dst += 2; |
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} |
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break; |
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case CODEC_ID_PCM_S8: |
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for(;n>0;n--) { |
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v = *samples++; |
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dst[0] = v >> 8; |
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dst++; |
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} |
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break; |
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case CODEC_ID_PCM_U8: |
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for(;n>0;n--) { |
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v = *samples++; |
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dst[0] = (v >> 8) + 128; |
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dst++; |
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} |
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break; |
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case CODEC_ID_PCM_ALAW: |
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for(;n>0;n--) { |
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v = *samples++; |
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dst[0] = linear_to_alaw[(v + 32768) >> 2]; |
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dst++; |
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} |
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break; |
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case CODEC_ID_PCM_MULAW: |
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for(;n>0;n--) { |
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v = *samples++; |
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dst[0] = linear_to_ulaw[(v + 32768) >> 2]; |
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dst++; |
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} |
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break; |
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default: |
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return -1; |
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} |
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//avctx->frame_size = (dst - frame) / (sample_size * avctx->channels); |
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return dst - frame; |
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} |
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typedef struct PCMDecode { |
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short table[256]; |
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} PCMDecode; |
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static int pcm_decode_init(AVCodecContext * avctx) |
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{ |
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PCMDecode *s = avctx->priv_data; |
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int i; |
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switch(avctx->codec->id) { |
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case CODEC_ID_PCM_ALAW: |
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for(i=0;i<256;i++) |
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s->table[i] = alaw2linear(i); |
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break; |
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case CODEC_ID_PCM_MULAW: |
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for(i=0;i<256;i++) |
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s->table[i] = ulaw2linear(i); |
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break; |
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default: |
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break; |
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} |
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return 0; |
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} |
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/** |
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* \brief convert samples to 16 bit |
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* \param bps byte per sample for the source format, must be >= 2 |
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* \param le 0 for big-, 1 for little-endian |
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* \param us 0 for signed, 1 for unsigned input |
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* \param src input samples |
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* \param samples output samples |
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* \param src_len number of bytes in src |
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*/ |
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static inline void decode_to16(int bps, int le, int us, |
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uint8_t **src, short **samples, int src_len) |
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{ |
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register int n = src_len / bps; |
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if (le) *src += bps - 2; |
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for(;n>0;n--) { |
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*(*samples)++ = ((*src)[le] << 8 | (*src)[1 - le]) - (us?0x8000:0); |
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*src += bps; |
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} |
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if (le) *src -= bps - 2; |
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} |
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static int pcm_decode_frame(AVCodecContext *avctx, |
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void *data, int *data_size, |
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uint8_t *buf, int buf_size) |
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{ |
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PCMDecode *s = avctx->priv_data; |
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int n; |
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short *samples; |
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uint8_t *src; |
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samples = data; |
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src = buf; |
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if(buf_size > AVCODEC_MAX_AUDIO_FRAME_SIZE/2) |
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buf_size = AVCODEC_MAX_AUDIO_FRAME_SIZE/2; |
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switch(avctx->codec->id) { |
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case CODEC_ID_PCM_S32LE: |
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decode_to16(4, 1, 0, &src, &samples, buf_size); |
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break; |
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case CODEC_ID_PCM_S32BE: |
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decode_to16(4, 0, 0, &src, &samples, buf_size); |
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break; |
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case CODEC_ID_PCM_U32LE: |
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decode_to16(4, 1, 1, &src, &samples, buf_size); |
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break; |
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case CODEC_ID_PCM_U32BE: |
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decode_to16(4, 0, 1, &src, &samples, buf_size); |
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break; |
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case CODEC_ID_PCM_S24LE: |
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decode_to16(3, 1, 0, &src, &samples, buf_size); |
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break; |
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case CODEC_ID_PCM_S24BE: |
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decode_to16(3, 0, 0, &src, &samples, buf_size); |
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break; |
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case CODEC_ID_PCM_U24LE: |
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decode_to16(3, 1, 1, &src, &samples, buf_size); |
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break; |
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case CODEC_ID_PCM_U24BE: |
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decode_to16(3, 0, 1, &src, &samples, buf_size); |
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break; |
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case CODEC_ID_PCM_S24DAUD: |
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n = buf_size / 3; |
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for(;n>0;n--) { |
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uint32_t v = src[0] << 16 | src[1] << 8 | src[2]; |
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v >>= 4; // sync flags are here |
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*samples++ = ff_reverse[(v >> 8) & 0xff] + |
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(ff_reverse[v & 0xff] << 8); |
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src += 3; |
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} |
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break; |
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case CODEC_ID_PCM_S16LE: |
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n = buf_size >> 1; |
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for(;n>0;n--) { |
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*samples++ = src[0] | (src[1] << 8); |
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src += 2; |
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} |
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break; |
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case CODEC_ID_PCM_S16BE: |
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n = buf_size >> 1; |
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for(;n>0;n--) { |
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*samples++ = (src[0] << 8) | src[1]; |
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src += 2; |
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} |
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break; |
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case CODEC_ID_PCM_U16LE: |
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n = buf_size >> 1; |
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for(;n>0;n--) { |
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*samples++ = (src[0] | (src[1] << 8)) - 0x8000; |
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src += 2; |
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} |
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break; |
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case CODEC_ID_PCM_U16BE: |
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n = buf_size >> 1; |
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for(;n>0;n--) { |
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*samples++ = ((src[0] << 8) | src[1]) - 0x8000; |
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src += 2; |
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} |
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break; |
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case CODEC_ID_PCM_S8: |
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n = buf_size; |
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for(;n>0;n--) { |
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*samples++ = src[0] << 8; |
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src++; |
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} |
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break; |
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case CODEC_ID_PCM_U8: |
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n = buf_size; |
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for(;n>0;n--) { |
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*samples++ = ((int)src[0] - 128) << 8; |
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src++; |
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} |
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break; |
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case CODEC_ID_PCM_ALAW: |
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case CODEC_ID_PCM_MULAW: |
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n = buf_size; |
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for(;n>0;n--) { |
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*samples++ = s->table[src[0]]; |
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src++; |
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} |
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break; |
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default: |
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return -1; |
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} |
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*data_size = (uint8_t *)samples - (uint8_t *)data; |
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return src - buf; |
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} |
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#define PCM_CODEC(id, name) \ |
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AVCodec name ## _encoder = { \ |
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#name, \ |
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CODEC_TYPE_AUDIO, \ |
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id, \ |
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0, \ |
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pcm_encode_init, \ |
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pcm_encode_frame, \ |
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pcm_encode_close, \ |
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NULL, \ |
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}; \ |
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AVCodec name ## _decoder = { \ |
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#name, \ |
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CODEC_TYPE_AUDIO, \ |
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id, \ |
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sizeof(PCMDecode), \ |
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pcm_decode_init, \ |
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NULL, \ |
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NULL, \ |
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pcm_decode_frame, \ |
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} |
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|
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PCM_CODEC(CODEC_ID_PCM_S32LE, pcm_s32le); |
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PCM_CODEC(CODEC_ID_PCM_S32BE, pcm_s32be); |
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PCM_CODEC(CODEC_ID_PCM_U32LE, pcm_u32le); |
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PCM_CODEC(CODEC_ID_PCM_U32BE, pcm_u32be); |
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PCM_CODEC(CODEC_ID_PCM_S24LE, pcm_s24le); |
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PCM_CODEC(CODEC_ID_PCM_S24BE, pcm_s24be); |
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PCM_CODEC(CODEC_ID_PCM_U24LE, pcm_u24le); |
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PCM_CODEC(CODEC_ID_PCM_U24BE, pcm_u24be); |
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PCM_CODEC(CODEC_ID_PCM_S24DAUD, pcm_s24daud); |
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PCM_CODEC(CODEC_ID_PCM_S16LE, pcm_s16le); |
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PCM_CODEC(CODEC_ID_PCM_S16BE, pcm_s16be); |
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PCM_CODEC(CODEC_ID_PCM_U16LE, pcm_u16le); |
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PCM_CODEC(CODEC_ID_PCM_U16BE, pcm_u16be); |
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PCM_CODEC(CODEC_ID_PCM_S8, pcm_s8); |
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PCM_CODEC(CODEC_ID_PCM_U8, pcm_u8); |
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PCM_CODEC(CODEC_ID_PCM_ALAW, pcm_alaw); |
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PCM_CODEC(CODEC_ID_PCM_MULAW, pcm_mulaw); |
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|
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#undef PCM_CODEC
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