0dce066f1eee0187117d36db732cd7d1ad24a65b
[libav.git] / libavcodec / eacmv.c
1 /*
2 * Electronic Arts CMV Video Decoder
3 * Copyright (c) 2007-2008 Peter Ross
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 St, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * Electronic Arts CMV Video Decoder
25 * by Peter Ross (pross@xvid.org)
26 *
27 * Technical details here:
28 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_CMV
29 */
30
31 #include "libavutil/common.h"
32 #include "libavutil/intreadwrite.h"
33 #include "libavutil/imgutils.h"
34 #include "avcodec.h"
35 #include "internal.h"
36
37 typedef struct CmvContext {
38 AVCodecContext *avctx;
39 AVFrame frame; ///< current
40 AVFrame last_frame; ///< last
41 AVFrame last2_frame; ///< second-last
42 int width, height;
43 unsigned int palette[AVPALETTE_COUNT];
44 } CmvContext;
45
46 static av_cold int cmv_decode_init(AVCodecContext *avctx){
47 CmvContext *s = avctx->priv_data;
48 s->avctx = avctx;
49 avctx->pix_fmt = AV_PIX_FMT_PAL8;
50 return 0;
51 }
52
53 static void cmv_decode_intra(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
54 unsigned char *dst = s->frame.data[0];
55 int i;
56
57 for (i=0; i < s->avctx->height && buf_end - buf >= s->avctx->width; i++) {
58 memcpy(dst, buf, s->avctx->width);
59 dst += s->frame.linesize[0];
60 buf += s->avctx->width;
61 }
62 }
63
64 static void cmv_motcomp(unsigned char *dst, int dst_stride,
65 const unsigned char *src, int src_stride,
66 int x, int y,
67 int xoffset, int yoffset,
68 int width, int height){
69 int i,j;
70
71 for(j=y;j<y+4;j++)
72 for(i=x;i<x+4;i++)
73 {
74 if (i+xoffset>=0 && i+xoffset<width &&
75 j+yoffset>=0 && j+yoffset<height) {
76 dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset];
77 }else{
78 dst[j*dst_stride + i] = 0;
79 }
80 }
81 }
82
83 static void cmv_decode_inter(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
84 const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16);
85 int x,y,i;
86
87 i = 0;
88 for(y=0; y<s->avctx->height/4; y++)
89 for(x=0; x<s->avctx->width/4 && buf_end - buf > i; x++) {
90 if (buf[i]==0xFF) {
91 unsigned char *dst = s->frame.data[0] + (y*4)*s->frame.linesize[0] + x*4;
92 if (raw+16<buf_end && *raw==0xFF) { /* intra */
93 raw++;
94 memcpy(dst, raw, 4);
95 memcpy(dst+s->frame.linesize[0], raw+4, 4);
96 memcpy(dst+2*s->frame.linesize[0], raw+8, 4);
97 memcpy(dst+3*s->frame.linesize[0], raw+12, 4);
98 raw+=16;
99 }else if(raw<buf_end) { /* inter using second-last frame as reference */
100 int xoffset = (*raw & 0xF) - 7;
101 int yoffset = ((*raw >> 4)) - 7;
102 if (s->last2_frame.data[0])
103 cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
104 s->last2_frame.data[0], s->last2_frame.linesize[0],
105 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
106 raw++;
107 }
108 }else{ /* inter using last frame as reference */
109 int xoffset = (buf[i] & 0xF) - 7;
110 int yoffset = ((buf[i] >> 4)) - 7;
111 cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
112 s->last_frame.data[0], s->last_frame.linesize[0],
113 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
114 }
115 i++;
116 }
117 }
118
119 static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end)
120 {
121 int pal_start, pal_count, i;
122
123 if(buf_end - buf < 16) {
124 av_log(s->avctx, AV_LOG_WARNING, "truncated header\n");
125 return;
126 }
127
128 s->width = AV_RL16(&buf[4]);
129 s->height = AV_RL16(&buf[6]);
130 if (s->avctx->width!=s->width || s->avctx->height!=s->height)
131 avcodec_set_dimensions(s->avctx, s->width, s->height);
132
133 s->avctx->time_base.num = 1;
134 s->avctx->time_base.den = AV_RL16(&buf[10]);
135
136 pal_start = AV_RL16(&buf[12]);
137 pal_count = AV_RL16(&buf[14]);
138
139 buf += 16;
140 for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
141 s->palette[i] = AV_RB24(buf);
142 buf += 3;
143 }
144 }
145
146 #define EA_PREAMBLE_SIZE 8
147 #define MVIh_TAG MKTAG('M', 'V', 'I', 'h')
148
149 static int cmv_decode_frame(AVCodecContext *avctx,
150 void *data, int *got_frame,
151 AVPacket *avpkt)
152 {
153 const uint8_t *buf = avpkt->data;
154 int buf_size = avpkt->size;
155 CmvContext *s = avctx->priv_data;
156 const uint8_t *buf_end = buf + buf_size;
157
158 if (buf_end - buf < EA_PREAMBLE_SIZE)
159 return AVERROR_INVALIDDATA;
160
161 if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) {
162 cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end);
163 return buf_size;
164 }
165
166 if (av_image_check_size(s->width, s->height, 0, s->avctx))
167 return -1;
168
169 /* shuffle */
170 if (s->last2_frame.data[0])
171 avctx->release_buffer(avctx, &s->last2_frame);
172 FFSWAP(AVFrame, s->last_frame, s->last2_frame);
173 FFSWAP(AVFrame, s->frame, s->last_frame);
174
175 s->frame.reference = 1;
176 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
177 if (ff_get_buffer(avctx, &s->frame)<0) {
178 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
179 return -1;
180 }
181
182 memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
183
184 buf += EA_PREAMBLE_SIZE;
185 if ((buf[0]&1)) { // subtype
186 cmv_decode_inter(s, buf+2, buf_end);
187 s->frame.key_frame = 0;
188 s->frame.pict_type = AV_PICTURE_TYPE_P;
189 }else{
190 s->frame.key_frame = 1;
191 s->frame.pict_type = AV_PICTURE_TYPE_I;
192 cmv_decode_intra(s, buf+2, buf_end);
193 }
194
195 *got_frame = 1;
196 *(AVFrame*)data = s->frame;
197
198 return buf_size;
199 }
200
201 static av_cold int cmv_decode_end(AVCodecContext *avctx){
202 CmvContext *s = avctx->priv_data;
203 if (s->frame.data[0])
204 s->avctx->release_buffer(avctx, &s->frame);
205 if (s->last_frame.data[0])
206 s->avctx->release_buffer(avctx, &s->last_frame);
207 if (s->last2_frame.data[0])
208 s->avctx->release_buffer(avctx, &s->last2_frame);
209
210 return 0;
211 }
212
213 AVCodec ff_eacmv_decoder = {
214 .name = "eacmv",
215 .type = AVMEDIA_TYPE_VIDEO,
216 .id = AV_CODEC_ID_CMV,
217 .priv_data_size = sizeof(CmvContext),
218 .init = cmv_decode_init,
219 .close = cmv_decode_end,
220 .decode = cmv_decode_frame,
221 .capabilities = CODEC_CAP_DR1,
222 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"),
223 };