lavc: add a wrapper for AVCodecContext.get_buffer().
[libav.git] / libavcodec / adxdec.c
1 /*
2 * ADX ADPCM codecs
3 * Copyright (c) 2001,2003 BERO
4 *
5 * This file is part of Libav.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 #include "libavutil/intreadwrite.h"
23 #include "avcodec.h"
24 #include "adx.h"
25 #include "get_bits.h"
26 #include "internal.h"
27
28 /**
29 * @file
30 * SEGA CRI adx codecs.
31 *
32 * Reference documents:
33 * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
34 * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
35 */
36
37 static av_cold int adx_decode_init(AVCodecContext *avctx)
38 {
39 ADXContext *c = avctx->priv_data;
40 int ret, header_size;
41
42 if (avctx->extradata_size >= 24) {
43 if ((ret = avpriv_adx_decode_header(avctx, avctx->extradata,
44 avctx->extradata_size, &header_size,
45 c->coeff)) < 0) {
46 av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
47 return AVERROR_INVALIDDATA;
48 }
49 c->channels = avctx->channels;
50 c->header_parsed = 1;
51 }
52
53 avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
54
55 avcodec_get_frame_defaults(&c->frame);
56 avctx->coded_frame = &c->frame;
57
58 return 0;
59 }
60
61 /**
62 * Decode 32 samples from 18 bytes.
63 *
64 * A 16-bit scalar value is applied to 32 residuals, which then have a
65 * 2nd-order LPC filter applied to it to form the output signal for a single
66 * channel.
67 */
68 static int adx_decode(ADXContext *c, int16_t *out, int offset,
69 const uint8_t *in, int ch)
70 {
71 ADXChannelState *prev = &c->prev[ch];
72 GetBitContext gb;
73 int scale = AV_RB16(in);
74 int i;
75 int s0, s1, s2, d;
76
77 /* check if this is an EOF packet */
78 if (scale & 0x8000)
79 return -1;
80
81 init_get_bits(&gb, in + 2, (BLOCK_SIZE - 2) * 8);
82 out += offset;
83 s1 = prev->s1;
84 s2 = prev->s2;
85 for (i = 0; i < BLOCK_SAMPLES; i++) {
86 d = get_sbits(&gb, 4);
87 s0 = ((d << COEFF_BITS) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS;
88 s2 = s1;
89 s1 = av_clip_int16(s0);
90 *out++ = s1;
91 }
92 prev->s1 = s1;
93 prev->s2 = s2;
94
95 return 0;
96 }
97
98 static int adx_decode_frame(AVCodecContext *avctx, void *data,
99 int *got_frame_ptr, AVPacket *avpkt)
100 {
101 int buf_size = avpkt->size;
102 ADXContext *c = avctx->priv_data;
103 int16_t **samples;
104 int samples_offset;
105 const uint8_t *buf = avpkt->data;
106 int num_blocks, ch, ret;
107
108 if (c->eof) {
109 *got_frame_ptr = 0;
110 return buf_size;
111 }
112
113 if (!c->header_parsed && buf_size >= 2 && AV_RB16(buf) == 0x8000) {
114 int header_size;
115 if ((ret = avpriv_adx_decode_header(avctx, buf, buf_size, &header_size,
116 c->coeff)) < 0) {
117 av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
118 return AVERROR_INVALIDDATA;
119 }
120 c->channels = avctx->channels;
121 c->header_parsed = 1;
122 if (buf_size < header_size)
123 return AVERROR_INVALIDDATA;
124 buf += header_size;
125 buf_size -= header_size;
126 }
127 if (!c->header_parsed)
128 return AVERROR_INVALIDDATA;
129
130 /* calculate number of blocks in the packet */
131 num_blocks = buf_size / (BLOCK_SIZE * c->channels);
132
133 /* if the packet is not an even multiple of BLOCK_SIZE, check for an EOF
134 packet */
135 if (!num_blocks || buf_size % (BLOCK_SIZE * avctx->channels)) {
136 if (buf_size >= 4 && (AV_RB16(buf) & 0x8000)) {
137 c->eof = 1;
138 *got_frame_ptr = 0;
139 return avpkt->size;
140 }
141 return AVERROR_INVALIDDATA;
142 }
143
144 /* get output buffer */
145 c->frame.nb_samples = num_blocks * BLOCK_SAMPLES;
146 if ((ret = ff_get_buffer(avctx, &c->frame)) < 0) {
147 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
148 return ret;
149 }
150 samples = (int16_t **)c->frame.extended_data;
151 samples_offset = 0;
152
153 while (num_blocks--) {
154 for (ch = 0; ch < c->channels; ch++) {
155 if (adx_decode(c, samples[ch], samples_offset, buf, ch)) {
156 c->eof = 1;
157 buf = avpkt->data + avpkt->size;
158 break;
159 }
160 buf_size -= BLOCK_SIZE;
161 buf += BLOCK_SIZE;
162 }
163 samples_offset += BLOCK_SAMPLES;
164 }
165
166 *got_frame_ptr = 1;
167 *(AVFrame *)data = c->frame;
168
169 return buf - avpkt->data;
170 }
171
172 static void adx_decode_flush(AVCodecContext *avctx)
173 {
174 ADXContext *c = avctx->priv_data;
175 memset(c->prev, 0, sizeof(c->prev));
176 c->eof = 0;
177 }
178
179 AVCodec ff_adpcm_adx_decoder = {
180 .name = "adpcm_adx",
181 .type = AVMEDIA_TYPE_AUDIO,
182 .id = AV_CODEC_ID_ADPCM_ADX,
183 .priv_data_size = sizeof(ADXContext),
184 .init = adx_decode_init,
185 .decode = adx_decode_frame,
186 .flush = adx_decode_flush,
187 .capabilities = CODEC_CAP_DR1,
188 .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
189 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
190 AV_SAMPLE_FMT_NONE },
191 };