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"
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 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 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 == 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 CODEC_ID_ROQ_DPCM:
195 case CODEC_ID_INTERPLAY_DPCM:
196 out = buf_size - 6 - s->channels;
198 case CODEC_ID_XAN_DPCM:
199 out = buf_size - 2 * s->channels;
201 case 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);
212 if (out % s->channels) {
213 av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
216 /* get output buffer */
217 s->frame.nb_samples = (out + s->channels - 1) / s->channels;
218 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
219 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
222 output_samples = (int16_t *)s->frame.data[0];
223 samples_end = output_samples + out;
225 switch(avctx->codec->id) {
227 case CODEC_ID_ROQ_DPCM:
228 bytestream2_skipu(&gb, 6);
231 predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
232 predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
234 predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
237 /* decode the samples */
238 while (output_samples < samples_end) {
239 predictor[ch] += s->roq_square_array[bytestream2_get_byteu(&gb)];
240 predictor[ch] = av_clip_int16(predictor[ch]);
241 *output_samples++ = predictor[ch];
248 case CODEC_ID_INTERPLAY_DPCM:
249 bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
251 for (ch = 0; ch < s->channels; ch++) {
252 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
253 *output_samples++ = predictor[ch];
257 while (output_samples < samples_end) {
258 predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
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] = sign_extend(bytestream2_get_le16u(&gb), 16);
275 while (output_samples < samples_end) {
276 int diff = bytestream2_get_byteu(&gb);
282 shift[ch] -= (2 * n);
283 diff = sign_extend((diff &~ 3) << 8, 16);
285 /* saturate the shifter to a lower limit of 0 */
290 predictor[ch] += diff;
292 predictor[ch] = av_clip_int16(predictor[ch]);
293 *output_samples++ = predictor[ch];
300 case CODEC_ID_SOL_DPCM:
301 if (avctx->codec_tag != 3) {
302 uint8_t *output_samples_u8 = s->frame.data[0],
303 *samples_end_u8 = output_samples_u8 + out;
304 while (output_samples_u8 < samples_end_u8) {
305 int n = bytestream2_get_byteu(&gb);
307 s->sample[0] += s->sol_table[n >> 4];
308 s->sample[0] = av_clip_uint8(s->sample[0]);
309 *output_samples_u8++ = s->sample[0];
311 s->sample[stereo] += s->sol_table[n & 0x0F];
312 s->sample[stereo] = av_clip_uint8(s->sample[stereo]);
313 *output_samples_u8++ = s->sample[stereo];
316 while (output_samples < samples_end) {
317 int n = bytestream2_get_byteu(&gb);
318 if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
319 else s->sample[ch] += sol_table_16[n & 0x7F];
320 s->sample[ch] = av_clip_int16(s->sample[ch]);
321 *output_samples++ = s->sample[ch];
330 *(AVFrame *)data = s->frame;
335 #define DPCM_DECODER(id_, name_, long_name_) \
336 AVCodec ff_ ## name_ ## _decoder = { \
338 .type = AVMEDIA_TYPE_AUDIO, \
340 .priv_data_size = sizeof(DPCMContext), \
341 .init = dpcm_decode_init, \
342 .decode = dpcm_decode_frame, \
343 .capabilities = CODEC_CAP_DR1, \
344 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
347 DPCM_DECODER(CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
348 DPCM_DECODER(CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
349 DPCM_DECODER(CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
350 DPCM_DECODER(CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");