| 
							- /*
 -  * PCM codecs
 -  * Copyright (c) 2001 Fabrice Bellard.
 -  *
 -  * 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 pcm.c
 -  * PCM codecs
 -  */
 - 
 - #include "avcodec.h"
 - #include "bitstream.h" // for ff_reverse
 - #include "bytestream.h"
 - 
 - #define MAX_CHANNELS 64
 - 
 - /* 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 av_cold 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 av_cold 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[16384];
 - static uint8_t linear_to_ulaw[16384];
 - 
 - static av_cold 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 av_cold int pcm_encode_init(AVCodecContext *avctx)
 - {
 -     avctx->frame_size = 1;
 -     switch(avctx->codec->id) {
 -     case CODEC_ID_PCM_ALAW:
 -         build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5);
 -         break;
 -     case CODEC_ID_PCM_MULAW:
 -         build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
 -         break;
 -     default:
 -         break;
 -     }
 - 
 -     switch(avctx->codec->id) {
 -     case CODEC_ID_PCM_S32LE:
 -     case CODEC_ID_PCM_S32BE:
 -     case CODEC_ID_PCM_U32LE:
 -     case CODEC_ID_PCM_U32BE:
 -         avctx->block_align = 4 * avctx->channels;
 -         break;
 -     case CODEC_ID_PCM_S24LE:
 -     case CODEC_ID_PCM_S24BE:
 -     case CODEC_ID_PCM_U24LE:
 -     case CODEC_ID_PCM_U24BE:
 -     case CODEC_ID_PCM_S24DAUD:
 -         avctx->block_align = 3 * avctx->channels;
 -         break;
 -     case CODEC_ID_PCM_S16LE:
 -     case CODEC_ID_PCM_S16BE:
 -     case CODEC_ID_PCM_U16LE:
 -     case CODEC_ID_PCM_U16BE:
 -         avctx->block_align = 2 * avctx->channels;
 -         break;
 -     case CODEC_ID_PCM_S8:
 -     case CODEC_ID_PCM_U8:
 -     case CODEC_ID_PCM_MULAW:
 -     case CODEC_ID_PCM_ALAW:
 -         avctx->block_align = avctx->channels;
 -         break;
 -     default:
 -         break;
 -     }
 - 
 -     avctx->coded_frame= avcodec_alloc_frame();
 -     avctx->coded_frame->key_frame= 1;
 - 
 -     return 0;
 - }
 - 
 - static av_cold int pcm_encode_close(AVCodecContext *avctx)
 - {
 -     av_freep(&avctx->coded_frame);
 - 
 -     return 0;
 - }
 - 
 - /**
 -  * \brief convert samples from 16 bit
 -  * \param bps byte per sample for the destination format, must be >= 2
 -  * \param le 0 for big-, 1 for little-endian
 -  * \param us 0 for signed, 1 for unsigned output
 -  * \param samples input samples
 -  * \param dst output samples
 -  * \param n number of samples in samples buffer.
 -  */
 - static inline void encode_from16(int bps, int le, int us,
 -                                short **samples, uint8_t **dst, int n) {
 -     int usum = us ? 0x8000 : 0;
 -     if (bps > 2)
 -         memset(*dst, 0, n * bps);
 -     if (le) *dst += bps - 2;
 -     for(;n>0;n--) {
 -         register int v = *(*samples)++;
 -         v += usum;
 -         if (le) AV_WL16(*dst, v);
 -         else    AV_WB16(*dst, v);
 -         *dst += bps;
 -     }
 -     if (le) *dst -= bps - 2;
 - }
 - 
 - 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_S32LE:
 -     case CODEC_ID_PCM_S32BE:
 -     case CODEC_ID_PCM_U32LE:
 -     case CODEC_ID_PCM_U32BE:
 -         sample_size = 4;
 -         break;
 -     case CODEC_ID_PCM_S24LE:
 -     case CODEC_ID_PCM_S24BE:
 -     case CODEC_ID_PCM_U24LE:
 -     case CODEC_ID_PCM_U24BE:
 -     case CODEC_ID_PCM_S24DAUD:
 -         sample_size = 3;
 -         break;
 -     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_S32LE:
 -         encode_from16(4, 1, 0, &samples, &dst, n);
 -         break;
 -     case CODEC_ID_PCM_S32BE:
 -         encode_from16(4, 0, 0, &samples, &dst, n);
 -         break;
 -     case CODEC_ID_PCM_U32LE:
 -         encode_from16(4, 1, 1, &samples, &dst, n);
 -         break;
 -     case CODEC_ID_PCM_U32BE:
 -         encode_from16(4, 0, 1, &samples, &dst, n);
 -         break;
 -     case CODEC_ID_PCM_S24LE:
 -         encode_from16(3, 1, 0, &samples, &dst, n);
 -         break;
 -     case CODEC_ID_PCM_S24BE:
 -         encode_from16(3, 0, 0, &samples, &dst, n);
 -         break;
 -     case CODEC_ID_PCM_U24LE:
 -         encode_from16(3, 1, 1, &samples, &dst, n);
 -         break;
 -     case CODEC_ID_PCM_U24BE:
 -         encode_from16(3, 0, 1, &samples, &dst, n);
 -         break;
 -     case CODEC_ID_PCM_S24DAUD:
 -         for(;n>0;n--) {
 -             uint32_t tmp = ff_reverse[*samples >> 8] +
 -                            (ff_reverse[*samples & 0xff] << 8);
 -             tmp <<= 4; // sync flags would go here
 -             bytestream_put_be24(&dst, tmp);
 -             samples++;
 -         }
 -         break;
 -     case CODEC_ID_PCM_S16LE:
 -         for(;n>0;n--) {
 -             v = *samples++;
 -             bytestream_put_le16(&dst, v);
 -         }
 -         break;
 -     case CODEC_ID_PCM_S16BE:
 -         for(;n>0;n--) {
 -             v = *samples++;
 -             bytestream_put_be16(&dst, v);
 -         }
 -         break;
 -     case CODEC_ID_PCM_U16LE:
 -         for(;n>0;n--) {
 -             v = *samples++;
 -             v += 0x8000;
 -             bytestream_put_le16(&dst, v);
 -         }
 -         break;
 -     case CODEC_ID_PCM_U16BE:
 -         for(;n>0;n--) {
 -             v = *samples++;
 -             v += 0x8000;
 -             bytestream_put_be16(&dst, v);
 -         }
 -         break;
 -     case CODEC_ID_PCM_S8:
 -         for(;n>0;n--) {
 -             v = *samples++;
 -             *dst++ = v >> 8;
 -         }
 -         break;
 -     case CODEC_ID_PCM_U8:
 -         for(;n>0;n--) {
 -             v = *samples++;
 -             *dst++ = (v >> 8) + 128;
 -         }
 -         break;
 -     case CODEC_ID_PCM_ZORK:
 -         for(;n>0;n--) {
 -             v= *samples++ >> 8;
 -             if(v<0)   v = -v;
 -             else      v+= 128;
 -             *dst++ = v;
 -         }
 -         break;
 -     case CODEC_ID_PCM_ALAW:
 -         for(;n>0;n--) {
 -             v = *samples++;
 -             *dst++ = linear_to_alaw[(v + 32768) >> 2];
 -         }
 -         break;
 -     case CODEC_ID_PCM_MULAW:
 -         for(;n>0;n--) {
 -             v = *samples++;
 -             *dst++ = linear_to_ulaw[(v + 32768) >> 2];
 -         }
 -         break;
 -     default:
 -         return -1;
 -     }
 -     //avctx->frame_size = (dst - frame) / (sample_size * avctx->channels);
 - 
 -     return dst - frame;
 - }
 - 
 - typedef struct PCMDecode {
 -     short table[256];
 - } PCMDecode;
 - 
 - static av_cold 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;
 - }
 - 
 - /**
 -  * \brief convert samples to 16 bit
 -  * \param bps byte per sample for the source format, must be >= 2
 -  * \param le 0 for big-, 1 for little-endian
 -  * \param us 0 for signed, 1 for unsigned input
 -  * \param src input samples
 -  * \param samples output samples
 -  * \param src_len number of bytes in src
 -  */
 - static inline void decode_to16(int bps, int le, int us,
 -                                const uint8_t **src, short **samples, int src_len)
 - {
 -     int usum = us ? -0x8000 : 0;
 -     register int n = src_len / bps;
 -     if (le) *src += bps - 2;
 -     for(;n>0;n--) {
 -         register int v;
 -         if (le) v = AV_RL16(*src);
 -         else    v = AV_RB16(*src);
 -         v += usum;
 -         *(*samples)++ = v;
 -         *src += bps;
 -     }
 -     if (le) *src -= bps - 2;
 - }
 - 
 - static int pcm_decode_frame(AVCodecContext *avctx,
 -                             void *data, int *data_size,
 -                             const uint8_t *buf, int buf_size)
 - {
 -     PCMDecode *s = avctx->priv_data;
 -     int c, n;
 -     short *samples;
 -     const uint8_t *src, *src2[MAX_CHANNELS];
 - 
 -     samples = data;
 -     src = buf;
 - 
 -     n= av_get_bits_per_sample(avctx->codec_id)/8;
 -     if(n && buf_size % n){
 -         av_log(avctx, AV_LOG_ERROR, "invalid PCM packet\n");
 -         return -1;
 -     }
 -     if(avctx->channels <= 0 || avctx->channels > MAX_CHANNELS){
 -         av_log(avctx, AV_LOG_ERROR, "PCM channels out of bounds\n");
 -         return -1;
 -     }
 - 
 -     buf_size= FFMIN(buf_size, *data_size/2);
 -     *data_size=0;
 - 
 -     n = buf_size/avctx->channels;
 -     for(c=0;c<avctx->channels;c++)
 -         src2[c] = &src[c*n];
 - 
 -     switch(avctx->codec->id) {
 -     case CODEC_ID_PCM_S32LE:
 -         decode_to16(4, 1, 0, &src, &samples, buf_size);
 -         break;
 -     case CODEC_ID_PCM_S32BE:
 -         decode_to16(4, 0, 0, &src, &samples, buf_size);
 -         break;
 -     case CODEC_ID_PCM_U32LE:
 -         decode_to16(4, 1, 1, &src, &samples, buf_size);
 -         break;
 -     case CODEC_ID_PCM_U32BE:
 -         decode_to16(4, 0, 1, &src, &samples, buf_size);
 -         break;
 -     case CODEC_ID_PCM_S24LE:
 -         decode_to16(3, 1, 0, &src, &samples, buf_size);
 -         break;
 -     case CODEC_ID_PCM_S24BE:
 -         decode_to16(3, 0, 0, &src, &samples, buf_size);
 -         break;
 -     case CODEC_ID_PCM_U24LE:
 -         decode_to16(3, 1, 1, &src, &samples, buf_size);
 -         break;
 -     case CODEC_ID_PCM_U24BE:
 -         decode_to16(3, 0, 1, &src, &samples, buf_size);
 -         break;
 -     case CODEC_ID_PCM_S24DAUD:
 -         n = buf_size / 3;
 -         for(;n>0;n--) {
 -           uint32_t v = bytestream_get_be24(&src);
 -           v >>= 4; // sync flags are here
 -           *samples++ = ff_reverse[(v >> 8) & 0xff] +
 -                        (ff_reverse[v & 0xff] << 8);
 -         }
 -         break;
 -     case CODEC_ID_PCM_S16LE:
 -         n = buf_size >> 1;
 -         for(;n>0;n--) {
 -             *samples++ = bytestream_get_le16(&src);
 -         }
 -         break;
 -     case CODEC_ID_PCM_S16LE_PLANAR:
 -         for(n>>=1;n>0;n--)
 -             for(c=0;c<avctx->channels;c++)
 -                 *samples++ = bytestream_get_le16(&src2[c]);
 -         src = src2[avctx->channels-1];
 -         break;
 -     case CODEC_ID_PCM_S16BE:
 -         n = buf_size >> 1;
 -         for(;n>0;n--) {
 -             *samples++ = bytestream_get_be16(&src);
 -         }
 -         break;
 -     case CODEC_ID_PCM_U16LE:
 -         n = buf_size >> 1;
 -         for(;n>0;n--) {
 -             *samples++ = bytestream_get_le16(&src) - 0x8000;
 -         }
 -         break;
 -     case CODEC_ID_PCM_U16BE:
 -         n = buf_size >> 1;
 -         for(;n>0;n--) {
 -             *samples++ = bytestream_get_be16(&src) - 0x8000;
 -         }
 -         break;
 -     case CODEC_ID_PCM_S8:
 -         n = buf_size;
 -         for(;n>0;n--) {
 -             *samples++ = *src++ << 8;
 -         }
 -         break;
 -     case CODEC_ID_PCM_U8:
 -         n = buf_size;
 -         for(;n>0;n--) {
 -             *samples++ = ((int)*src++ - 128) << 8;
 -         }
 -         break;
 -     case CODEC_ID_PCM_ZORK:
 -         n = buf_size;
 -         for(;n>0;n--) {
 -             int x= *src++;
 -             if(x&128) x-= 128;
 -             else      x = -x;
 -             *samples++ = x << 8;
 -         }
 -         break;
 -     case CODEC_ID_PCM_ALAW:
 -     case CODEC_ID_PCM_MULAW:
 -         n = buf_size;
 -         for(;n>0;n--) {
 -             *samples++ = s->table[*src++];
 -         }
 -         break;
 -     default:
 -         return -1;
 -     }
 -     *data_size = (uint8_t *)samples - (uint8_t *)data;
 -     return src - buf;
 - }
 - 
 - #ifdef CONFIG_ENCODERS
 - #define PCM_ENCODER(id,name)                    \
 - AVCodec name ## _encoder = {                    \
 -     #name,                                      \
 -     CODEC_TYPE_AUDIO,                           \
 -     id,                                         \
 -     0,                                          \
 -     pcm_encode_init,                            \
 -     pcm_encode_frame,                           \
 -     pcm_encode_close,                           \
 -     NULL,                                       \
 - };
 - #else
 - #define PCM_ENCODER(id,name)
 - #endif
 - 
 - #ifdef CONFIG_DECODERS
 - #define PCM_DECODER(id,name)                    \
 - AVCodec name ## _decoder = {                    \
 -     #name,                                      \
 -     CODEC_TYPE_AUDIO,                           \
 -     id,                                         \
 -     sizeof(PCMDecode),                          \
 -     pcm_decode_init,                            \
 -     NULL,                                       \
 -     NULL,                                       \
 -     pcm_decode_frame,                           \
 - };
 - #else
 - #define PCM_DECODER(id,name)
 - #endif
 - 
 - #define PCM_CODEC(id, name)                     \
 - PCM_ENCODER(id,name) PCM_DECODER(id,name)
 - 
 - PCM_CODEC  (CODEC_ID_PCM_ALAW, pcm_alaw);
 - PCM_CODEC  (CODEC_ID_PCM_MULAW, pcm_mulaw);
 - PCM_CODEC  (CODEC_ID_PCM_S8, pcm_s8);
 - PCM_CODEC  (CODEC_ID_PCM_S16BE, pcm_s16be);
 - PCM_CODEC  (CODEC_ID_PCM_S16LE, pcm_s16le);
 - PCM_DECODER(CODEC_ID_PCM_S16LE_PLANAR, pcm_s16le_planar);
 - PCM_CODEC  (CODEC_ID_PCM_S24BE, pcm_s24be);
 - PCM_CODEC  (CODEC_ID_PCM_S24DAUD, pcm_s24daud);
 - PCM_CODEC  (CODEC_ID_PCM_S24LE, pcm_s24le);
 - PCM_CODEC  (CODEC_ID_PCM_S32BE, pcm_s32be);
 - PCM_CODEC  (CODEC_ID_PCM_S32LE, pcm_s32le);
 - PCM_CODEC  (CODEC_ID_PCM_U8, pcm_u8);
 - PCM_CODEC  (CODEC_ID_PCM_U16BE, pcm_u16be);
 - PCM_CODEC  (CODEC_ID_PCM_U16LE, pcm_u16le);
 - PCM_CODEC  (CODEC_ID_PCM_U24BE, pcm_u24be);
 - PCM_CODEC  (CODEC_ID_PCM_U24LE, pcm_u24le);
 - PCM_CODEC  (CODEC_ID_PCM_U32BE, pcm_u32be);
 - PCM_CODEC  (CODEC_ID_PCM_U32LE, pcm_u32le);
 - PCM_CODEC  (CODEC_ID_PCM_ZORK, pcm_zork);
 
 
  |