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"
44 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->channels = avctx->channels;
126 s->sample[0] = s->sample[1] = 0;
128 switch(avctx->codec->id) {
130 case 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 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 == 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 const uint8_t *buf = avpkt->data;
177 int buf_size = avpkt->size;
178 const uint8_t *buf_end = buf + buf_size;
179 DPCMContext *s = avctx->priv_data;
183 int stereo = s->channels - 1;
184 int16_t *output_samples;
186 /* calculate output size */
187 switch(avctx->codec->id) {
188 case CODEC_ID_ROQ_DPCM:
191 case CODEC_ID_INTERPLAY_DPCM:
192 out = buf_size - 6 - s->channels;
194 case CODEC_ID_XAN_DPCM:
195 out = buf_size - 2 * s->channels;
197 case 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 s->frame.nb_samples = out / s->channels;
211 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
212 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
215 output_samples = (int16_t *)s->frame.data[0];
217 switch(avctx->codec->id) {
219 case CODEC_ID_ROQ_DPCM:
223 predictor[1] = (int16_t)(bytestream_get_byte(&buf) << 8);
224 predictor[0] = (int16_t)(bytestream_get_byte(&buf) << 8);
226 predictor[0] = (int16_t)bytestream_get_le16(&buf);
229 /* decode the samples */
230 while (buf < buf_end) {
231 predictor[ch] += s->roq_square_array[*buf++];
232 predictor[ch] = av_clip_int16(predictor[ch]);
233 *output_samples++ = predictor[ch];
240 case CODEC_ID_INTERPLAY_DPCM:
241 buf += 6; /* skip over the stream mask and stream length */
243 for (ch = 0; ch < s->channels; ch++) {
244 predictor[ch] = (int16_t)bytestream_get_le16(&buf);
245 *output_samples++ = predictor[ch];
249 while (buf < buf_end) {
250 predictor[ch] += interplay_delta_table[*buf++];
251 predictor[ch] = av_clip_int16(predictor[ch]);
252 *output_samples++ = predictor[ch];
259 case CODEC_ID_XAN_DPCM:
261 int shift[2] = { 4, 4 };
263 for (ch = 0; ch < s->channels; ch++)
264 predictor[ch] = (int16_t)bytestream_get_le16(&buf);
267 while (buf < buf_end) {
269 int16_t diff = (n & 0xFC) << 8;
273 shift[ch] -= (2 * (n & 3));
274 /* saturate the shifter to a lower limit of 0 */
279 predictor[ch] += diff;
281 predictor[ch] = av_clip_int16(predictor[ch]);
282 *output_samples++ = predictor[ch];
289 case CODEC_ID_SOL_DPCM:
290 if (avctx->codec_tag != 3) {
291 uint8_t *output_samples_u8 = s->frame.data[0];
292 while (buf < buf_end) {
295 s->sample[0] += s->sol_table[n >> 4];
296 s->sample[0] = av_clip_uint8(s->sample[0]);
297 *output_samples_u8++ = s->sample[0];
299 s->sample[stereo] += s->sol_table[n & 0x0F];
300 s->sample[stereo] = av_clip_uint8(s->sample[stereo]);
301 *output_samples_u8++ = s->sample[stereo];
304 while (buf < buf_end) {
306 if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
307 else s->sample[ch] += sol_table_16[n & 0x7F];
308 s->sample[ch] = av_clip_int16(s->sample[ch]);
309 *output_samples++ = s->sample[ch];
318 *(AVFrame *)data = s->frame;
323 #define DPCM_DECODER(id_, name_, long_name_) \
324 AVCodec ff_ ## name_ ## _decoder = { \
326 .type = AVMEDIA_TYPE_AUDIO, \
328 .priv_data_size = sizeof(DPCMContext), \
329 .init = dpcm_decode_init, \
330 .decode = dpcm_decode_frame, \
331 .capabilities = CODEC_CAP_DR1, \
332 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
335 DPCM_DECODER(CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
336 DPCM_DECODER(CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
337 DPCM_DECODER(CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
338 DPCM_DECODER(CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");