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authorMike Melanson <mike@multimedia.cx>2003-09-02 04:32:02 +0000
committerMike Melanson <mike@multimedia.cx>2003-09-02 04:32:02 +0000
commit3ef8be2bfc89672060a2a2f2b8926b3decb08172 (patch)
tree10889fe4d2d844deed4952a7f82416ee6bcb9692 /libavcodec/dpcm.c
parent149f7c029ccdc649dc9ee523f1dcf23ab8d0f6ac (diff)
downloadffmpeg-3ef8be2bfc89672060a2a2f2b8926b3decb08172.tar.gz
initial commit for Id RoQ and Interplay MVE multimedia subsystems
Originally committed as revision 2195 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/dpcm.c')
-rw-r--r--libavcodec/dpcm.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/libavcodec/dpcm.c b/libavcodec/dpcm.c
new file mode 100644
index 0000000000..bd3ad7fd0f
--- /dev/null
+++ b/libavcodec/dpcm.c
@@ -0,0 +1,200 @@
+/*
+ * Assorted DPCM codecs
+ * Copyright (c) 2003 The ffmpeg Project.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/**
+ * @file: dpcm.c
+ * Assorted DPCM (differential pulse code modulation) audio codecs
+ * by Mike Melanson (melanson@pcisys.net)
+ * for more information on the specific data formats, visit:
+ * http://www.pcisys.net/~melanson/codecs/simpleaudio.html
+ */
+
+#include "avcodec.h"
+
+typedef struct DPCMContext {
+ int channels;
+ short roq_square_array[256];
+ int last_delta[2];
+} DPCMContext;
+
+#define SATURATE_S16(x) if (x < -32768) x = -32768; \
+ else if (x > 32767) x = 32767;
+#define SE_16BIT(x) if (x & 0x8000) x -= 0x10000;
+#define LE_16(x) ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0])
+#define LE_32(x) ((((uint8_t*)(x))[3] << 24) | \
+ (((uint8_t*)(x))[2] << 16) | \
+ (((uint8_t*)(x))[1] << 8) | \
+ ((uint8_t*)(x))[0])
+
+static int interplay_delta_table[] = {
+ 0, 1, 2, 3, 4, 5, 6, 7,
+ 8, 9, 10, 11, 12, 13, 14, 15,
+ 16, 17, 18, 19, 20, 21, 22, 23,
+ 24, 25, 26, 27, 28, 29, 30, 31,
+ 32, 33, 34, 35, 36, 37, 38, 39,
+ 40, 41, 42, 43, 47, 51, 56, 61,
+ 66, 72, 79, 86, 94, 102, 112, 122,
+ 133, 145, 158, 173, 189, 206, 225, 245,
+ 267, 292, 318, 348, 379, 414, 452, 493,
+ 538, 587, 640, 699, 763, 832, 908, 991,
+ 1081, 1180, 1288, 1405, 1534, 1673, 1826, 1993,
+ 2175, 2373, 2590, 2826, 3084, 3365, 3672, 4008,
+ 4373, 4772, 5208, 5683, 6202, 6767, 7385, 8059,
+ 8794, 9597, 10472, 11428, 12471, 13609, 14851, 16206,
+ 17685, 19298, 21060, 22981, 25078, 27367, 29864, 32589,
+ -29973, -26728, -23186, -19322, -15105, -10503, -5481, -1,
+ 1, 1, 5481, 10503, 15105, 19322, 23186, 26728,
+ 29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298,
+ -17685, -16206, -14851, -13609, -12471, -11428, -10472, -9597,
+ -8794, -8059, -7385, -6767, -6202, -5683, -5208, -4772,
+ -4373, -4008, -3672, -3365, -3084, -2826, -2590, -2373,
+ -2175, -1993, -1826, -1673, -1534, -1405, -1288, -1180,
+ -1081, -991, -908, -832, -763, -699, -640, -587,
+ -538, -493, -452, -414, -379, -348, -318, -292,
+ -267, -245, -225, -206, -189, -173, -158, -145,
+ -133, -122, -112, -102, -94, -86, -79, -72,
+ -66, -61, -56, -51, -47, -43, -42, -41,
+ -40, -39, -38, -37, -36, -35, -34, -33,
+ -32, -31, -30, -29, -28, -27, -26, -25,
+ -24, -23, -22, -21, -20, -19, -18, -17,
+ -16, -15, -14, -13, -12, -11, -10, -9,
+ -8, -7, -6, -5, -4, -3, -2, -1
+
+};
+
+static int dpcm_decode_init(AVCodecContext *avctx)
+{
+ DPCMContext *s = avctx->priv_data;
+ int i;
+ short square;
+
+ s->channels = avctx->channels;
+
+ switch(avctx->codec->id) {
+
+ case CODEC_ID_ROQ_DPCM:
+ /* initialize square table */
+ for (i = 0; i < 128; i++) {
+ square = i * i;
+ s->roq_square_array[i] = square;
+ s->roq_square_array[i + 128] = -square;
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int dpcm_decode_frame(AVCodecContext *avctx,
+ void *data, int *data_size,
+ uint8_t *buf, int buf_size)
+{
+ DPCMContext *s = avctx->priv_data;
+ int in, out = 0;
+ int i;
+ int predictor[2];
+ int channel_number = 0;
+ short *output_samples = data;
+ int sequence_number;
+
+ switch(avctx->codec->id) {
+
+ case CODEC_ID_ROQ_DPCM:
+ if (s->channels == 1)
+ predictor[0] = LE_16(&buf[6]);
+ else {
+ predictor[0] = buf[7] << 8;
+ predictor[1] = buf[6] << 8;
+ }
+ SE_16BIT(predictor[0]);
+ SE_16BIT(predictor[1]);
+
+ /* decode the samples */
+ for (in = 8, out = 0; in < buf_size; in++, out++) {
+ predictor[channel_number] += s->roq_square_array[buf[in]];
+ SATURATE_S16(predictor[channel_number]);
+ output_samples[out] = predictor[channel_number];
+
+ /* toggle channel */
+ channel_number ^= s->channels - 1;
+ }
+ break;
+
+ case CODEC_ID_INTERPLAY_DPCM:
+ in = 0;
+ sequence_number = LE_16(&buf[in]);
+ in += 6; /* skip over the stream mask and stream length */
+ if (sequence_number == 1) {
+ predictor[0] = LE_16(&buf[in]);
+ in += 2;
+ SE_16BIT(predictor[0])
+ if (s->channels == 2) {
+ predictor[1] = LE_16(&buf[in]);
+ SE_16BIT(predictor[1])
+ in += 2;
+ }
+ } else {
+ for (i = 0; i < s->channels; i++)
+ predictor[i] = s->last_delta[i];
+ }
+
+ while (in < buf_size) {
+ predictor[channel_number] += interplay_delta_table[buf[in++]];
+ SATURATE_S16(predictor[channel_number]);
+ output_samples[out++] = predictor[channel_number];
+
+ /* toggle channel */
+ channel_number ^= s->channels - 1;
+ }
+
+ /* save predictors for next round */
+ for (i = 0; i < s->channels; i++)
+ s->last_delta[i] = predictor[i];
+
+ break;
+ }
+
+ *data_size = out * sizeof(short);
+ return buf_size;
+}
+
+AVCodec roq_dpcm_decoder = {
+ "roq_dpcm",
+ CODEC_TYPE_AUDIO,
+ CODEC_ID_ROQ_DPCM,
+ sizeof(DPCMContext),
+ dpcm_decode_init,
+ NULL,
+ NULL,
+ dpcm_decode_frame,
+};
+
+AVCodec interplay_dpcm_decoder = {
+ "interplay_dpcm",
+ CODEC_TYPE_AUDIO,
+ CODEC_ID_INTERPLAY_DPCM,
+ sizeof(DPCMContext),
+ dpcm_decode_init,
+ NULL,
+ NULL,
+ dpcm_decode_frame,
+};