3 * Copyright (c) 2003 The ffmpeg Project
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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 {
48 int16_t roq_square_array[256];
49 int sample[2]; ///< previous sample (for SOL_DPCM)
50 const int8_t *sol_table; ///< delta table for SOL_DPCM
53 static const int16_t interplay_delta_table[] = {
54 0, 1, 2, 3, 4, 5, 6, 7,
55 8, 9, 10, 11, 12, 13, 14, 15,
56 16, 17, 18, 19, 20, 21, 22, 23,
57 24, 25, 26, 27, 28, 29, 30, 31,
58 32, 33, 34, 35, 36, 37, 38, 39,
59 40, 41, 42, 43, 47, 51, 56, 61,
60 66, 72, 79, 86, 94, 102, 112, 122,
61 133, 145, 158, 173, 189, 206, 225, 245,
62 267, 292, 318, 348, 379, 414, 452, 493,
63 538, 587, 640, 699, 763, 832, 908, 991,
64 1081, 1180, 1288, 1405, 1534, 1673, 1826, 1993,
65 2175, 2373, 2590, 2826, 3084, 3365, 3672, 4008,
66 4373, 4772, 5208, 5683, 6202, 6767, 7385, 8059,
67 8794, 9597, 10472, 11428, 12471, 13609, 14851, 16206,
68 17685, 19298, 21060, 22981, 25078, 27367, 29864, 32589,
69 -29973, -26728, -23186, -19322, -15105, -10503, -5481, -1,
70 1, 1, 5481, 10503, 15105, 19322, 23186, 26728,
71 29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298,
72 -17685, -16206, -14851, -13609, -12471, -11428, -10472, -9597,
73 -8794, -8059, -7385, -6767, -6202, -5683, -5208, -4772,
74 -4373, -4008, -3672, -3365, -3084, -2826, -2590, -2373,
75 -2175, -1993, -1826, -1673, -1534, -1405, -1288, -1180,
76 -1081, -991, -908, -832, -763, -699, -640, -587,
77 -538, -493, -452, -414, -379, -348, -318, -292,
78 -267, -245, -225, -206, -189, -173, -158, -145,
79 -133, -122, -112, -102, -94, -86, -79, -72,
80 -66, -61, -56, -51, -47, -43, -42, -41,
81 -40, -39, -38, -37, -36, -35, -34, -33,
82 -32, -31, -30, -29, -28, -27, -26, -25,
83 -24, -23, -22, -21, -20, -19, -18, -17,
84 -16, -15, -14, -13, -12, -11, -10, -9,
85 -8, -7, -6, -5, -4, -3, -2, -1
89 static const int8_t sol_table_old[16] = {
90 0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
91 -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0
94 static const int8_t sol_table_new[16] = {
95 0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
96 0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15
99 static const int16_t sol_table_16[128] = {
100 0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
101 0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
102 0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
103 0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
104 0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
105 0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
106 0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
107 0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
108 0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
109 0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
110 0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
111 0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
112 0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
116 static av_cold int dpcm_decode_init(AVCodecContext *avctx)
118 DPCMContext *s = avctx->priv_data;
121 if (avctx->channels < 1 || avctx->channels > 2) {
122 av_log(avctx, AV_LOG_INFO, "invalid number of channels\n");
123 return AVERROR(EINVAL);
126 s->sample[0] = s->sample[1] = 0;
128 switch(avctx->codec->id) {
130 case AV_CODEC_ID_ROQ_DPCM:
131 /* initialize square table */
132 for (i = 0; i < 128; i++) {
133 int16_t square = i * i;
134 s->roq_square_array[i ] = square;
135 s->roq_square_array[i + 128] = -square;
139 case AV_CODEC_ID_SOL_DPCM:
140 switch(avctx->codec_tag){
142 s->sol_table = sol_table_old;
143 s->sample[0] = s->sample[1] = 0x80;
146 s->sol_table = sol_table_new;
147 s->sample[0] = s->sample[1] = 0x80;
152 av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
161 if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
162 avctx->sample_fmt = AV_SAMPLE_FMT_U8;
164 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
166 avcodec_get_frame_defaults(&s->frame);
167 avctx->coded_frame = &s->frame;
173 static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
174 int *got_frame_ptr, AVPacket *avpkt)
176 int buf_size = avpkt->size;
177 DPCMContext *s = avctx->priv_data;
181 int stereo = avctx->channels - 1;
182 int16_t *output_samples, *samples_end;
185 if (stereo && (buf_size & 1))
187 bytestream2_init(&gb, avpkt->data, buf_size);
189 /* calculate output size */
190 switch(avctx->codec->id) {
191 case AV_CODEC_ID_ROQ_DPCM:
194 case AV_CODEC_ID_INTERPLAY_DPCM:
195 out = buf_size - 6 - avctx->channels;
197 case AV_CODEC_ID_XAN_DPCM:
198 out = buf_size - 2 * avctx->channels;
200 case AV_CODEC_ID_SOL_DPCM:
201 if (avctx->codec_tag != 3)
208 av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
209 return AVERROR(EINVAL);
212 /* get output buffer */
213 s->frame.nb_samples = out / avctx->channels;
214 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
215 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
218 output_samples = (int16_t *)s->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 = s->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];
326 *(AVFrame *)data = s->frame;
331 #define DPCM_DECODER(id_, name_, long_name_) \
332 AVCodec ff_ ## name_ ## _decoder = { \
334 .type = AVMEDIA_TYPE_AUDIO, \
336 .priv_data_size = sizeof(DPCMContext), \
337 .init = dpcm_decode_init, \
338 .decode = dpcm_decode_frame, \
339 .capabilities = CODEC_CAP_DR1, \
340 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
343 DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
344 DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
345 DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
346 DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");