| /* |
| * Assorted DPCM codecs |
| * Copyright (c) 2003 The ffmpeg Project |
| * |
| * 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: dpcm.c |
| * Assorted DPCM (differential pulse code modulation) audio codecs |
| * by Mike Melanson (melanson@pcisys.net) |
| * Xan DPCM decoder by Mario Brito (mbrito@student.dei.uc.pt) |
| * for more information on the specific data formats, visit: |
| * http://www.pcisys.net/~melanson/codecs/simpleaudio.html |
| * SOL DPCMs implemented by Konstantin Shishkov |
| * |
| * Note about using the Xan DPCM decoder: Xan DPCM is used in AVI files |
| * found in the Wing Commander IV computer game. These AVI files contain |
| * WAVEFORMAT headers which report the audio format as 0x01: raw PCM. |
| * Clearly incorrect. To detect Xan DPCM, you will probably have to |
| * special-case your AVI demuxer to use Xan DPCM if the file uses 'Xxan' |
| * (Xan video) for its video codec. Alternately, such AVI files also contain |
| * the fourcc 'Axan' in the 'auds' chunk of the AVI header. |
| */ |
| |
| #include "libavutil/intreadwrite.h" |
| #include "avcodec.h" |
| |
| typedef struct DPCMContext { |
| int channels; |
| short roq_square_array[256]; |
| long sample[2];//for SOL_DPCM |
| const int *sol_table;//for SOL_DPCM |
| } DPCMContext; |
| |
| #define SE_16BIT(x) if (x & 0x8000) x -= 0x10000; |
| |
| static const 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 const int sol_table_old[16] = |
| { 0x0, 0x1, 0x2 , 0x3, 0x6, 0xA, 0xF, 0x15, |
| -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0}; |
| |
| static const int sol_table_new[16] = |
| { 0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15, |
| 0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15}; |
| |
| static const int sol_table_16[128] = { |
| 0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080, |
| 0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120, |
| 0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0, |
| 0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230, |
| 0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280, |
| 0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0, |
| 0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320, |
| 0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370, |
| 0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0, |
| 0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480, |
| 0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700, |
| 0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00, |
| 0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000 |
| }; |
| |
| |
| |
| static av_cold int dpcm_decode_init(AVCodecContext *avctx) |
| { |
| DPCMContext *s = avctx->priv_data; |
| int i; |
| short square; |
| |
| s->channels = avctx->channels; |
| s->sample[0] = s->sample[1] = 0; |
| |
| 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; |
| |
| |
| case CODEC_ID_SOL_DPCM: |
| switch(avctx->codec_tag){ |
| case 1: |
| s->sol_table=sol_table_old; |
| s->sample[0] = s->sample[1] = 0x80; |
| break; |
| case 2: |
| s->sol_table=sol_table_new; |
| s->sample[0] = s->sample[1] = 0x80; |
| break; |
| case 3: |
| s->sol_table=sol_table_16; |
| break; |
| default: |
| av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n"); |
| return -1; |
| } |
| break; |
| |
| default: |
| break; |
| } |
| |
| avctx->sample_fmt = SAMPLE_FMT_S16; |
| return 0; |
| } |
| |
| static int dpcm_decode_frame(AVCodecContext *avctx, |
| void *data, int *data_size, |
| const uint8_t *buf, int buf_size) |
| { |
| DPCMContext *s = avctx->priv_data; |
| int in, out = 0; |
| int predictor[2]; |
| int channel_number = 0; |
| int stereo = s->channels - 1; |
| short *output_samples = data; |
| int shift[2]; |
| unsigned char byte; |
| short diff; |
| |
| if (!buf_size) |
| return 0; |
| |
| if (stereo && (buf_size & 1)) |
| buf_size--; |
| |
| // almost every DPCM variant expands one byte of data into two |
| if(*data_size/2 < buf_size) |
| return -1; |
| |
| switch(avctx->codec->id) { |
| |
| case CODEC_ID_ROQ_DPCM: |
| if (s->channels == 1) |
| predictor[0] = AV_RL16(&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]]; |
| predictor[channel_number] = av_clip_int16(predictor[channel_number]); |
| output_samples[out] = predictor[channel_number]; |
| |
| /* toggle channel */ |
| channel_number ^= s->channels - 1; |
| } |
| break; |
| |
| case CODEC_ID_INTERPLAY_DPCM: |
| in = 6; /* skip over the stream mask and stream length */ |
| predictor[0] = AV_RL16(&buf[in]); |
| in += 2; |
| SE_16BIT(predictor[0]) |
| output_samples[out++] = predictor[0]; |
| if (s->channels == 2) { |
| predictor[1] = AV_RL16(&buf[in]); |
| in += 2; |
| SE_16BIT(predictor[1]) |
| output_samples[out++] = predictor[1]; |
| } |
| |
| while (in < buf_size) { |
| predictor[channel_number] += interplay_delta_table[buf[in++]]; |
| predictor[channel_number] = av_clip_int16(predictor[channel_number]); |
| output_samples[out++] = predictor[channel_number]; |
| |
| /* toggle channel */ |
| channel_number ^= s->channels - 1; |
| } |
| |
| break; |
| |
| case CODEC_ID_XAN_DPCM: |
| in = 0; |
| shift[0] = shift[1] = 4; |
| predictor[0] = AV_RL16(&buf[in]); |
| in += 2; |
| SE_16BIT(predictor[0]); |
| if (s->channels == 2) { |
| predictor[1] = AV_RL16(&buf[in]); |
| in += 2; |
| SE_16BIT(predictor[1]); |
| } |
| |
| while (in < buf_size) { |
| byte = buf[in++]; |
| diff = (byte & 0xFC) << 8; |
| if ((byte & 0x03) == 3) |
| shift[channel_number]++; |
| else |
| shift[channel_number] -= (2 * (byte & 3)); |
| /* saturate the shifter to a lower limit of 0 */ |
| if (shift[channel_number] < 0) |
| shift[channel_number] = 0; |
| |
| diff >>= shift[channel_number]; |
| predictor[channel_number] += diff; |
| |
| predictor[channel_number] = av_clip_int16(predictor[channel_number]); |
| output_samples[out++] = predictor[channel_number]; |
| |
| /* toggle channel */ |
| channel_number ^= s->channels - 1; |
| } |
| break; |
| case CODEC_ID_SOL_DPCM: |
| in = 0; |
| if (avctx->codec_tag != 3) { |
| if(*data_size/4 < buf_size) |
| return -1; |
| while (in < buf_size) { |
| int n1, n2; |
| n1 = (buf[in] >> 4) & 0xF; |
| n2 = buf[in++] & 0xF; |
| s->sample[0] += s->sol_table[n1]; |
| if (s->sample[0] < 0) s->sample[0] = 0; |
| if (s->sample[0] > 255) s->sample[0] = 255; |
| output_samples[out++] = (s->sample[0] - 128) << 8; |
| s->sample[s->channels - 1] += s->sol_table[n2]; |
| if (s->sample[s->channels - 1] < 0) s->sample[s->channels - 1] = 0; |
| if (s->sample[s->channels - 1] > 255) s->sample[s->channels - 1] = 255; |
| output_samples[out++] = (s->sample[s->channels - 1] - 128) << 8; |
| } |
| } else { |
| while (in < buf_size) { |
| int n; |
| n = buf[in++]; |
| if (n & 0x80) s->sample[channel_number] -= s->sol_table[n & 0x7F]; |
| else s->sample[channel_number] += s->sol_table[n & 0x7F]; |
| s->sample[channel_number] = av_clip_int16(s->sample[channel_number]); |
| output_samples[out++] = s->sample[channel_number]; |
| /* toggle channel */ |
| channel_number ^= s->channels - 1; |
| } |
| } |
| break; |
| } |
| |
| *data_size = out * sizeof(short); |
| return buf_size; |
| } |
| |
| #define DPCM_DECODER(id, name, long_name_) \ |
| AVCodec name ## _decoder = { \ |
| #name, \ |
| CODEC_TYPE_AUDIO, \ |
| id, \ |
| sizeof(DPCMContext), \ |
| dpcm_decode_init, \ |
| NULL, \ |
| NULL, \ |
| dpcm_decode_frame, \ |
| .long_name = NULL_IF_CONFIG_SMALL(long_name_), \ |
| }; |
| |
| DPCM_DECODER(CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay"); |
| DPCM_DECODER(CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ"); |
| DPCM_DECODER(CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol"); |
| DPCM_DECODER(CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan"); |
