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 {
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_INFO, "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);
209 /* get output buffer */
210 frame->nb_samples = out / avctx->channels;
211 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
212 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
215 output_samples = (int16_t *)frame->data[0];
216 samples_end = output_samples + out;
218 switch(avctx->codec->id) {
220 case AV_CODEC_ID_ROQ_DPCM:
221 bytestream2_skipu(&gb, 6);
224 predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
225 predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
227 predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
230 /* decode the samples */
231 while (output_samples < samples_end) {
232 predictor[ch] += s->roq_square_array[bytestream2_get_byteu(&gb)];
233 predictor[ch] = av_clip_int16(predictor[ch]);
234 *output_samples++ = predictor[ch];
241 case AV_CODEC_ID_INTERPLAY_DPCM:
242 bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
244 for (ch = 0; ch < avctx->channels; ch++) {
245 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
246 *output_samples++ = predictor[ch];
250 while (output_samples < samples_end) {
251 predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
252 predictor[ch] = av_clip_int16(predictor[ch]);
253 *output_samples++ = predictor[ch];
260 case AV_CODEC_ID_XAN_DPCM:
262 int shift[2] = { 4, 4 };
264 for (ch = 0; ch < avctx->channels; ch++)
265 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
268 while (output_samples < samples_end) {
269 int diff = bytestream2_get_byteu(&gb);
275 shift[ch] -= (2 * n);
276 diff = sign_extend((diff &~ 3) << 8, 16);
278 /* saturate the shifter to a lower limit of 0 */
283 predictor[ch] += diff;
285 predictor[ch] = av_clip_int16(predictor[ch]);
286 *output_samples++ = predictor[ch];
293 case AV_CODEC_ID_SOL_DPCM:
294 if (avctx->codec_tag != 3) {
295 uint8_t *output_samples_u8 = frame->data[0],
296 *samples_end_u8 = output_samples_u8 + out;
297 while (output_samples_u8 < samples_end_u8) {
298 int n = bytestream2_get_byteu(&gb);
300 s->sample[0] += s->sol_table[n >> 4];
301 s->sample[0] = av_clip_uint8(s->sample[0]);
302 *output_samples_u8++ = s->sample[0];
304 s->sample[stereo] += s->sol_table[n & 0x0F];
305 s->sample[stereo] = av_clip_uint8(s->sample[stereo]);
306 *output_samples_u8++ = s->sample[stereo];
309 while (output_samples < samples_end) {
310 int n = bytestream2_get_byteu(&gb);
311 if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
312 else s->sample[ch] += sol_table_16[n & 0x7F];
313 s->sample[ch] = av_clip_int16(s->sample[ch]);
314 *output_samples++ = s->sample[ch];
327 #define DPCM_DECODER(id_, name_, long_name_) \
328 AVCodec ff_ ## name_ ## _decoder = { \
330 .type = AVMEDIA_TYPE_AUDIO, \
332 .priv_data_size = sizeof(DPCMContext), \
333 .init = dpcm_decode_init, \
334 .decode = dpcm_decode_frame, \
335 .capabilities = CODEC_CAP_DR1, \
336 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
339 DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
340 DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
341 DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
342 DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");