3 * Copyright (c) 2003 The ffmpeg Project
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * Assorted DPCM (differential pulse code modulation) audio codecs
25 * by Mike Melanson (melanson@pcisys.net)
26 * Xan DPCM decoder by Mario Brito (mbrito@student.dei.uc.pt)
27 * for more information on the specific data formats, visit:
28 * http://www.pcisys.net/~melanson/codecs/simpleaudio.html
29 * SOL DPCMs implemented by Konstantin Shishkov
31 * Note about using the Xan DPCM decoder: Xan DPCM is used in AVI files
32 * found in the Wing Commander IV computer game. These AVI files contain
33 * WAVEFORMAT headers which report the audio format as 0x01: raw PCM.
34 * Clearly incorrect. To detect Xan DPCM, you will probably have to
35 * special-case your AVI demuxer to use Xan DPCM if the file uses 'Xxan'
36 * (Xan video) for its video codec. Alternately, such AVI files also contain
37 * the fourcc 'Axan' in the 'auds' chunk of the AVI header.
40 #include "libavutil/intreadwrite.h"
42 #include "bytestream.h"
46 typedef struct DPCMContext {
47 int16_t roq_square_array[256];
48 int sample[2]; ///< previous sample (for SOL_DPCM)
49 const int8_t *sol_table; ///< delta table for SOL_DPCM
52 static const int16_t interplay_delta_table[] = {
53 0, 1, 2, 3, 4, 5, 6, 7,
54 8, 9, 10, 11, 12, 13, 14, 15,
55 16, 17, 18, 19, 20, 21, 22, 23,
56 24, 25, 26, 27, 28, 29, 30, 31,
57 32, 33, 34, 35, 36, 37, 38, 39,
58 40, 41, 42, 43, 47, 51, 56, 61,
59 66, 72, 79, 86, 94, 102, 112, 122,
60 133, 145, 158, 173, 189, 206, 225, 245,
61 267, 292, 318, 348, 379, 414, 452, 493,
62 538, 587, 640, 699, 763, 832, 908, 991,
63 1081, 1180, 1288, 1405, 1534, 1673, 1826, 1993,
64 2175, 2373, 2590, 2826, 3084, 3365, 3672, 4008,
65 4373, 4772, 5208, 5683, 6202, 6767, 7385, 8059,
66 8794, 9597, 10472, 11428, 12471, 13609, 14851, 16206,
67 17685, 19298, 21060, 22981, 25078, 27367, 29864, 32589,
68 -29973, -26728, -23186, -19322, -15105, -10503, -5481, -1,
69 1, 1, 5481, 10503, 15105, 19322, 23186, 26728,
70 29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298,
71 -17685, -16206, -14851, -13609, -12471, -11428, -10472, -9597,
72 -8794, -8059, -7385, -6767, -6202, -5683, -5208, -4772,
73 -4373, -4008, -3672, -3365, -3084, -2826, -2590, -2373,
74 -2175, -1993, -1826, -1673, -1534, -1405, -1288, -1180,
75 -1081, -991, -908, -832, -763, -699, -640, -587,
76 -538, -493, -452, -414, -379, -348, -318, -292,
77 -267, -245, -225, -206, -189, -173, -158, -145,
78 -133, -122, -112, -102, -94, -86, -79, -72,
79 -66, -61, -56, -51, -47, -43, -42, -41,
80 -40, -39, -38, -37, -36, -35, -34, -33,
81 -32, -31, -30, -29, -28, -27, -26, -25,
82 -24, -23, -22, -21, -20, -19, -18, -17,
83 -16, -15, -14, -13, -12, -11, -10, -9,
84 -8, -7, -6, -5, -4, -3, -2, -1
88 static const int8_t sol_table_old[16] = {
89 0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
90 -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0
93 static const int8_t sol_table_new[16] = {
94 0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
95 0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15
98 static const int16_t sol_table_16[128] = {
99 0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
100 0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
101 0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
102 0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
103 0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
104 0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
105 0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
106 0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
107 0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
108 0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
109 0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
110 0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
111 0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
115 static av_cold int dpcm_decode_init(AVCodecContext *avctx)
117 DPCMContext *s = avctx->priv_data;
120 if (avctx->channels < 1 || avctx->channels > 2) {
121 av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
122 return AVERROR(EINVAL);
125 s->sample[0] = s->sample[1] = 0;
127 switch(avctx->codec->id) {
129 case AV_CODEC_ID_ROQ_DPCM:
130 /* initialize square table */
131 for (i = 0; i < 128; i++) {
132 int16_t square = i * i;
133 s->roq_square_array[i ] = square;
134 s->roq_square_array[i + 128] = -square;
138 case AV_CODEC_ID_SOL_DPCM:
139 switch(avctx->codec_tag){
141 s->sol_table = sol_table_old;
142 s->sample[0] = s->sample[1] = 0x80;
145 s->sol_table = sol_table_new;
146 s->sample[0] = s->sample[1] = 0x80;
151 av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
160 if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
161 avctx->sample_fmt = AV_SAMPLE_FMT_U8;
163 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
169 static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
170 int *got_frame_ptr, AVPacket *avpkt)
172 int buf_size = avpkt->size;
173 DPCMContext *s = avctx->priv_data;
174 AVFrame *frame = data;
178 int stereo = avctx->channels - 1;
179 int16_t *output_samples, *samples_end;
182 if (stereo && (buf_size & 1))
184 bytestream2_init(&gb, avpkt->data, buf_size);
186 /* calculate output size */
187 switch(avctx->codec->id) {
188 case AV_CODEC_ID_ROQ_DPCM:
191 case AV_CODEC_ID_INTERPLAY_DPCM:
192 out = buf_size - 6 - avctx->channels;
194 case AV_CODEC_ID_XAN_DPCM:
195 out = buf_size - 2 * avctx->channels;
197 case AV_CODEC_ID_SOL_DPCM:
198 if (avctx->codec_tag != 3)
205 av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
206 return AVERROR(EINVAL);
208 if (out % avctx->channels) {
209 av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
212 /* get output buffer */
213 frame->nb_samples = (out + avctx->channels - 1) / avctx->channels;
214 if ((ret = ff_get_buffer(avctx, frame)) < 0) {
215 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
218 output_samples = (int16_t *)frame->data[0];
219 samples_end = output_samples + out;
221 switch(avctx->codec->id) {
223 case AV_CODEC_ID_ROQ_DPCM:
224 bytestream2_skipu(&gb, 6);
227 predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
228 predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
230 predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
233 /* decode the samples */
234 while (output_samples < samples_end) {
235 predictor[ch] += s->roq_square_array[bytestream2_get_byteu(&gb)];
236 predictor[ch] = av_clip_int16(predictor[ch]);
237 *output_samples++ = predictor[ch];
244 case AV_CODEC_ID_INTERPLAY_DPCM:
245 bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
247 for (ch = 0; ch < avctx->channels; ch++) {
248 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
249 *output_samples++ = predictor[ch];
253 while (output_samples < samples_end) {
254 predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
255 predictor[ch] = av_clip_int16(predictor[ch]);
256 *output_samples++ = predictor[ch];
263 case AV_CODEC_ID_XAN_DPCM:
265 int shift[2] = { 4, 4 };
267 for (ch = 0; ch < avctx->channels; ch++)
268 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
271 while (output_samples < samples_end) {
272 int diff = bytestream2_get_byteu(&gb);
278 shift[ch] -= (2 * n);
279 diff = sign_extend((diff &~ 3) << 8, 16);
281 /* saturate the shifter to a lower limit of 0 */
286 predictor[ch] += diff;
288 predictor[ch] = av_clip_int16(predictor[ch]);
289 *output_samples++ = predictor[ch];
296 case AV_CODEC_ID_SOL_DPCM:
297 if (avctx->codec_tag != 3) {
298 uint8_t *output_samples_u8 = frame->data[0],
299 *samples_end_u8 = output_samples_u8 + out;
300 while (output_samples_u8 < samples_end_u8) {
301 int n = bytestream2_get_byteu(&gb);
303 s->sample[0] += s->sol_table[n >> 4];
304 s->sample[0] = av_clip_uint8(s->sample[0]);
305 *output_samples_u8++ = s->sample[0];
307 s->sample[stereo] += s->sol_table[n & 0x0F];
308 s->sample[stereo] = av_clip_uint8(s->sample[stereo]);
309 *output_samples_u8++ = s->sample[stereo];
312 while (output_samples < samples_end) {
313 int n = bytestream2_get_byteu(&gb);
314 if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
315 else s->sample[ch] += sol_table_16[n & 0x7F];
316 s->sample[ch] = av_clip_int16(s->sample[ch]);
317 *output_samples++ = s->sample[ch];
330 #define DPCM_DECODER(id_, name_, long_name_) \
331 AVCodec ff_ ## name_ ## _decoder = { \
333 .type = AVMEDIA_TYPE_AUDIO, \
335 .priv_data_size = sizeof(DPCMContext), \
336 .init = dpcm_decode_init, \
337 .decode = dpcm_decode_frame, \
338 .capabilities = CODEC_CAP_DR1, \
339 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
342 DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
343 DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
344 DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
345 DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");