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"
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 if (stereo && (buf_size & 1)) {
191 /* calculate output size */
192 switch(avctx->codec->id) {
193 case CODEC_ID_ROQ_DPCM:
196 case CODEC_ID_INTERPLAY_DPCM:
197 out = buf_size - 6 - s->channels;
199 case CODEC_ID_XAN_DPCM:
200 out = buf_size - 2 * s->channels;
202 case CODEC_ID_SOL_DPCM:
203 if (avctx->codec_tag != 3)
210 av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
211 return AVERROR(EINVAL);
213 if (out % s->channels) {
214 av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
217 /* get output buffer */
218 s->frame.nb_samples = (out + s->channels - 1) / s->channels;
219 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
220 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
223 output_samples = (int16_t *)s->frame.data[0];
225 switch(avctx->codec->id) {
227 case CODEC_ID_ROQ_DPCM:
231 predictor[1] = (int16_t)(bytestream_get_byte(&buf) << 8);
232 predictor[0] = (int16_t)(bytestream_get_byte(&buf) << 8);
234 predictor[0] = (int16_t)bytestream_get_le16(&buf);
237 /* decode the samples */
238 while (buf < buf_end) {
239 predictor[ch] += s->roq_square_array[*buf++];
240 predictor[ch] = av_clip_int16(predictor[ch]);
241 *output_samples++ = predictor[ch];
248 case CODEC_ID_INTERPLAY_DPCM:
249 buf += 6; /* skip over the stream mask and stream length */
251 for (ch = 0; ch < s->channels; ch++) {
252 predictor[ch] = (int16_t)bytestream_get_le16(&buf);
253 *output_samples++ = predictor[ch];
257 while (buf < buf_end) {
258 predictor[ch] += interplay_delta_table[*buf++];
259 predictor[ch] = av_clip_int16(predictor[ch]);
260 *output_samples++ = predictor[ch];
267 case CODEC_ID_XAN_DPCM:
269 int shift[2] = { 4, 4 };
271 for (ch = 0; ch < s->channels; ch++)
272 predictor[ch] = (int16_t)bytestream_get_le16(&buf);
275 while (buf < buf_end) {
277 int16_t diff = (n & 0xFC) << 8;
281 shift[ch] -= (2 * (n & 3));
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 CODEC_ID_SOL_DPCM:
298 if (avctx->codec_tag != 3) {
299 uint8_t *output_samples_u8 = s->frame.data[0];
300 while (buf < buf_end) {
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 (buf < buf_end) {
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(CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
344 DPCM_DECODER(CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
345 DPCM_DECODER(CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
346 DPCM_DECODER(CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");