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author | Mike Melanson <mike@multimedia.cx> | 2003-09-02 04:32:02 +0000 |
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committer | Mike Melanson <mike@multimedia.cx> | 2003-09-02 04:32:02 +0000 |
commit | 3ef8be2bfc89672060a2a2f2b8926b3decb08172 (patch) | |
tree | 10889fe4d2d844deed4952a7f82416ee6bcb9692 /libavcodec/dpcm.c | |
parent | 149f7c029ccdc649dc9ee523f1dcf23ab8d0f6ac (diff) | |
download | ffmpeg-3ef8be2bfc89672060a2a2f2b8926b3decb08172.tar.gz |
initial commit for Id RoQ and Interplay MVE multimedia subsystems
Originally committed as revision 2195 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/dpcm.c')
-rw-r--r-- | libavcodec/dpcm.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/libavcodec/dpcm.c b/libavcodec/dpcm.c new file mode 100644 index 0000000000..bd3ad7fd0f --- /dev/null +++ b/libavcodec/dpcm.c @@ -0,0 +1,200 @@ +/* + * Assorted DPCM codecs + * Copyright (c) 2003 The ffmpeg Project. + * + * 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: dpcm.c + * Assorted DPCM (differential pulse code modulation) audio codecs + * by Mike Melanson (melanson@pcisys.net) + * for more information on the specific data formats, visit: + * http://www.pcisys.net/~melanson/codecs/simpleaudio.html + */ + +#include "avcodec.h" + +typedef struct DPCMContext { + int channels; + short roq_square_array[256]; + int last_delta[2]; +} DPCMContext; + +#define SATURATE_S16(x) if (x < -32768) x = -32768; \ + else if (x > 32767) x = 32767; +#define SE_16BIT(x) if (x & 0x8000) x -= 0x10000; +#define LE_16(x) ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0]) +#define LE_32(x) ((((uint8_t*)(x))[3] << 24) | \ + (((uint8_t*)(x))[2] << 16) | \ + (((uint8_t*)(x))[1] << 8) | \ + ((uint8_t*)(x))[0]) + +static int interplay_delta_table[] = { + 0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 16, 17, 18, 19, 20, 21, 22, 23, + 24, 25, 26, 27, 28, 29, 30, 31, + 32, 33, 34, 35, 36, 37, 38, 39, + 40, 41, 42, 43, 47, 51, 56, 61, + 66, 72, 79, 86, 94, 102, 112, 122, + 133, 145, 158, 173, 189, 206, 225, 245, + 267, 292, 318, 348, 379, 414, 452, 493, + 538, 587, 640, 699, 763, 832, 908, 991, + 1081, 1180, 1288, 1405, 1534, 1673, 1826, 1993, + 2175, 2373, 2590, 2826, 3084, 3365, 3672, 4008, + 4373, 4772, 5208, 5683, 6202, 6767, 7385, 8059, + 8794, 9597, 10472, 11428, 12471, 13609, 14851, 16206, + 17685, 19298, 21060, 22981, 25078, 27367, 29864, 32589, + -29973, -26728, -23186, -19322, -15105, -10503, -5481, -1, + 1, 1, 5481, 10503, 15105, 19322, 23186, 26728, + 29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298, + -17685, -16206, -14851, -13609, -12471, -11428, -10472, -9597, + -8794, -8059, -7385, -6767, -6202, -5683, -5208, -4772, + -4373, -4008, -3672, -3365, -3084, -2826, -2590, -2373, + -2175, -1993, -1826, -1673, -1534, -1405, -1288, -1180, + -1081, -991, -908, -832, -763, -699, -640, -587, + -538, -493, -452, -414, -379, -348, -318, -292, + -267, -245, -225, -206, -189, -173, -158, -145, + -133, -122, -112, -102, -94, -86, -79, -72, + -66, -61, -56, -51, -47, -43, -42, -41, + -40, -39, -38, -37, -36, -35, -34, -33, + -32, -31, -30, -29, -28, -27, -26, -25, + -24, -23, -22, -21, -20, -19, -18, -17, + -16, -15, -14, -13, -12, -11, -10, -9, + -8, -7, -6, -5, -4, -3, -2, -1 + +}; + +static int dpcm_decode_init(AVCodecContext *avctx) +{ + DPCMContext *s = avctx->priv_data; + int i; + short square; + + s->channels = avctx->channels; + + switch(avctx->codec->id) { + + case CODEC_ID_ROQ_DPCM: + /* initialize square table */ + for (i = 0; i < 128; i++) { + square = i * i; + s->roq_square_array[i] = square; + s->roq_square_array[i + 128] = -square; + } + break; + + default: + break; + } + + return 0; +} + +static int dpcm_decode_frame(AVCodecContext *avctx, + void *data, int *data_size, + uint8_t *buf, int buf_size) +{ + DPCMContext *s = avctx->priv_data; + int in, out = 0; + int i; + int predictor[2]; + int channel_number = 0; + short *output_samples = data; + int sequence_number; + + switch(avctx->codec->id) { + + case CODEC_ID_ROQ_DPCM: + if (s->channels == 1) + predictor[0] = LE_16(&buf[6]); + else { + predictor[0] = buf[7] << 8; + predictor[1] = buf[6] << 8; + } + SE_16BIT(predictor[0]); + SE_16BIT(predictor[1]); + + /* decode the samples */ + for (in = 8, out = 0; in < buf_size; in++, out++) { + predictor[channel_number] += s->roq_square_array[buf[in]]; + SATURATE_S16(predictor[channel_number]); + output_samples[out] = predictor[channel_number]; + + /* toggle channel */ + channel_number ^= s->channels - 1; + } + break; + + case CODEC_ID_INTERPLAY_DPCM: + in = 0; + sequence_number = LE_16(&buf[in]); + in += 6; /* skip over the stream mask and stream length */ + if (sequence_number == 1) { + predictor[0] = LE_16(&buf[in]); + in += 2; + SE_16BIT(predictor[0]) + if (s->channels == 2) { + predictor[1] = LE_16(&buf[in]); + SE_16BIT(predictor[1]) + in += 2; + } + } else { + for (i = 0; i < s->channels; i++) + predictor[i] = s->last_delta[i]; + } + + while (in < buf_size) { + predictor[channel_number] += interplay_delta_table[buf[in++]]; + SATURATE_S16(predictor[channel_number]); + output_samples[out++] = predictor[channel_number]; + + /* toggle channel */ + channel_number ^= s->channels - 1; + } + + /* save predictors for next round */ + for (i = 0; i < s->channels; i++) + s->last_delta[i] = predictor[i]; + + break; + } + + *data_size = out * sizeof(short); + return buf_size; +} + +AVCodec roq_dpcm_decoder = { + "roq_dpcm", + CODEC_TYPE_AUDIO, + CODEC_ID_ROQ_DPCM, + sizeof(DPCMContext), + dpcm_decode_init, + NULL, + NULL, + dpcm_decode_frame, +}; + +AVCodec interplay_dpcm_decoder = { + "interplay_dpcm", + CODEC_TYPE_AUDIO, + CODEC_ID_INTERPLAY_DPCM, + sizeof(DPCMContext), + dpcm_decode_init, + NULL, + NULL, + dpcm_decode_frame, +}; |