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"
45 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->channels = avctx->channels;
127 s->sample[0] = s->sample[1] = 0;
129 switch(avctx->codec->id) {
131 case AV_CODEC_ID_ROQ_DPCM:
132 /* initialize square table */
133 for (i = 0; i < 128; i++) {
134 int16_t square = i * i;
135 s->roq_square_array[i ] = square;
136 s->roq_square_array[i + 128] = -square;
140 case AV_CODEC_ID_SOL_DPCM:
141 switch(avctx->codec_tag){
143 s->sol_table = sol_table_old;
144 s->sample[0] = s->sample[1] = 0x80;
147 s->sol_table = sol_table_new;
148 s->sample[0] = s->sample[1] = 0x80;
153 av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
162 if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
163 avctx->sample_fmt = AV_SAMPLE_FMT_U8;
165 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
167 avcodec_get_frame_defaults(&s->frame);
168 avctx->coded_frame = &s->frame;
174 static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
175 int *got_frame_ptr, AVPacket *avpkt)
177 int buf_size = avpkt->size;
178 DPCMContext *s = avctx->priv_data;
182 int stereo = s->channels - 1;
183 int16_t *output_samples, *samples_end;
186 if (stereo && (buf_size & 1))
188 bytestream2_init(&gb, avpkt->data, buf_size);
190 /* calculate output size */
191 switch(avctx->codec->id) {
192 case AV_CODEC_ID_ROQ_DPCM:
195 case AV_CODEC_ID_INTERPLAY_DPCM:
196 out = buf_size - 6 - s->channels;
198 case AV_CODEC_ID_XAN_DPCM:
199 out = buf_size - 2 * s->channels;
201 case AV_CODEC_ID_SOL_DPCM:
202 if (avctx->codec_tag != 3)
209 av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
210 return AVERROR(EINVAL);
213 /* get output buffer */
214 s->frame.nb_samples = out / s->channels;
215 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
216 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
219 output_samples = (int16_t *)s->frame.data[0];
220 samples_end = output_samples + out;
222 switch(avctx->codec->id) {
224 case AV_CODEC_ID_ROQ_DPCM:
225 bytestream2_skipu(&gb, 6);
228 predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
229 predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
231 predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
234 /* decode the samples */
235 while (output_samples < samples_end) {
236 predictor[ch] += s->roq_square_array[bytestream2_get_byteu(&gb)];
237 predictor[ch] = av_clip_int16(predictor[ch]);
238 *output_samples++ = predictor[ch];
245 case AV_CODEC_ID_INTERPLAY_DPCM:
246 bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
248 for (ch = 0; ch < s->channels; ch++) {
249 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
250 *output_samples++ = predictor[ch];
254 while (output_samples < samples_end) {
255 predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
256 predictor[ch] = av_clip_int16(predictor[ch]);
257 *output_samples++ = predictor[ch];
264 case AV_CODEC_ID_XAN_DPCM:
266 int shift[2] = { 4, 4 };
268 for (ch = 0; ch < s->channels; ch++)
269 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
272 while (output_samples < samples_end) {
273 int diff = bytestream2_get_byteu(&gb);
279 shift[ch] -= (2 * n);
280 diff = sign_extend((diff &~ 3) << 8, 16);
282 /* saturate the shifter to a lower limit of 0 */
287 predictor[ch] += diff;
289 predictor[ch] = av_clip_int16(predictor[ch]);
290 *output_samples++ = predictor[ch];
297 case AV_CODEC_ID_SOL_DPCM:
298 if (avctx->codec_tag != 3) {
299 uint8_t *output_samples_u8 = s->frame.data[0],
300 *samples_end_u8 = output_samples_u8 + out;
301 while (output_samples_u8 < samples_end_u8) {
302 int n = bytestream2_get_byteu(&gb);
304 s->sample[0] += s->sol_table[n >> 4];
305 s->sample[0] = av_clip_uint8(s->sample[0]);
306 *output_samples_u8++ = s->sample[0];
308 s->sample[stereo] += s->sol_table[n & 0x0F];
309 s->sample[stereo] = av_clip_uint8(s->sample[stereo]);
310 *output_samples_u8++ = s->sample[stereo];
313 while (output_samples < samples_end) {
314 int n = bytestream2_get_byteu(&gb);
315 if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
316 else s->sample[ch] += sol_table_16[n & 0x7F];
317 s->sample[ch] = av_clip_int16(s->sample[ch]);
318 *output_samples++ = s->sample[ch];
327 *(AVFrame *)data = s->frame;
332 #define DPCM_DECODER(id_, name_, long_name_) \
333 AVCodec ff_ ## name_ ## _decoder = { \
335 .type = AVMEDIA_TYPE_AUDIO, \
337 .priv_data_size = sizeof(DPCMContext), \
338 .init = dpcm_decode_init, \
339 .decode = dpcm_decode_frame, \
340 .capabilities = CODEC_CAP_DR1, \
341 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
344 DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
345 DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
346 DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
347 DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");