1 /*
2 * Electronic Arts CMV Video Decoder
3 * Copyright (c) 2007-2008 Peter Ross
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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 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 *last_frame; ///< last
40 AVFrame *last2_frame; ///< second-last
41 int width, height;
42 unsigned int palette[AVPALETTE_COUNT];
43 } CmvContext;
44
cmv_decode_init(AVCodecContext * avctx)45 static av_cold int cmv_decode_init(AVCodecContext *avctx){
46 CmvContext *s = avctx->priv_data;
47
48 s->avctx = avctx;
49 avctx->pix_fmt = AV_PIX_FMT_PAL8;
50
51 s->last_frame = av_frame_alloc();
52 s->last2_frame = av_frame_alloc();
53 if (!s->last_frame || !s->last2_frame)
54 return AVERROR(ENOMEM);
55
56 return 0;
57 }
58
cmv_decode_intra(CmvContext * s,AVFrame * frame,const uint8_t * buf,const uint8_t * buf_end)59 static void cmv_decode_intra(CmvContext * s, AVFrame *frame,
60 const uint8_t *buf, const uint8_t *buf_end)
61 {
62 unsigned char *dst = frame->data[0];
63 int i;
64
65 for (i=0; i < s->avctx->height && buf_end - buf >= s->avctx->width; i++) {
66 memcpy(dst, buf, s->avctx->width);
67 dst += frame->linesize[0];
68 buf += s->avctx->width;
69 }
70 }
71
cmv_motcomp(unsigned char * dst,ptrdiff_t dst_stride,const unsigned char * src,ptrdiff_t src_stride,int x,int y,int xoffset,int yoffset,int width,int height)72 static void cmv_motcomp(unsigned char *dst, ptrdiff_t dst_stride,
73 const unsigned char *src, ptrdiff_t src_stride,
74 int x, int y,
75 int xoffset, int yoffset,
76 int width, int height){
77 int i,j;
78
79 for(j=y;j<y+4;j++)
80 for(i=x;i<x+4;i++)
81 {
82 if (i+xoffset>=0 && i+xoffset<width &&
83 j+yoffset>=0 && j+yoffset<height) {
84 dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset];
85 }else{
86 dst[j*dst_stride + i] = 0;
87 }
88 }
89 }
90
cmv_decode_inter(CmvContext * s,AVFrame * frame,const uint8_t * buf,const uint8_t * buf_end)91 static void cmv_decode_inter(CmvContext *s, AVFrame *frame, const uint8_t *buf,
92 const uint8_t *buf_end)
93 {
94 const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16);
95 int x,y,i;
96
97 i = 0;
98 for(y=0; y<s->avctx->height/4; y++)
99 for(x=0; x<s->avctx->width/4 && buf_end - buf > i; x++) {
100 if (buf[i]==0xFF) {
101 unsigned char *dst = frame->data[0] + (y*4)*frame->linesize[0] + x*4;
102 if (raw+16<buf_end && *raw==0xFF) { /* intra */
103 raw++;
104 memcpy(dst, raw, 4);
105 memcpy(dst + frame->linesize[0], raw+4, 4);
106 memcpy(dst + 2 * frame->linesize[0], raw+8, 4);
107 memcpy(dst + 3 * frame->linesize[0], raw+12, 4);
108 raw+=16;
109 }else if(raw<buf_end) { /* inter using second-last frame as reference */
110 int xoffset = (*raw & 0xF) - 7;
111 int yoffset = ((*raw >> 4)) - 7;
112 if (s->last2_frame->data[0])
113 cmv_motcomp(frame->data[0], frame->linesize[0],
114 s->last2_frame->data[0], s->last2_frame->linesize[0],
115 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
116 raw++;
117 }
118 }else{ /* inter using last frame as reference */
119 int xoffset = (buf[i] & 0xF) - 7;
120 int yoffset = ((buf[i] >> 4)) - 7;
121 if (s->last_frame->data[0])
122 cmv_motcomp(frame->data[0], frame->linesize[0],
123 s->last_frame->data[0], s->last_frame->linesize[0],
124 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
125 }
126 i++;
127 }
128 }
129
cmv_process_header(CmvContext * s,const uint8_t * buf,const uint8_t * buf_end)130 static int cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end)
131 {
132 int pal_start, pal_count, i, ret, fps;
133
134 if(buf_end - buf < 16) {
135 av_log(s->avctx, AV_LOG_WARNING, "truncated header\n");
136 return AVERROR_INVALIDDATA;
137 }
138
139 s->width = AV_RL16(&buf[4]);
140 s->height = AV_RL16(&buf[6]);
141
142 if (s->width != s->avctx->width ||
143 s->height != s->avctx->height) {
144 av_frame_unref(s->last_frame);
145 av_frame_unref(s->last2_frame);
146 }
147
148 ret = ff_set_dimensions(s->avctx, s->width, s->height);
149 if (ret < 0)
150 return ret;
151
152 fps = AV_RL16(&buf[10]);
153 if (fps > 0)
154 s->avctx->framerate = (AVRational){ fps, 1 };
155
156 pal_start = AV_RL16(&buf[12]);
157 pal_count = AV_RL16(&buf[14]);
158
159 buf += 16;
160 for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
161 s->palette[i] = 0xFFU << 24 | AV_RB24(buf);
162 buf += 3;
163 }
164
165 return 0;
166 }
167
168 #define EA_PREAMBLE_SIZE 8
169 #define MVIh_TAG MKTAG('M', 'V', 'I', 'h')
170
cmv_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)171 static int cmv_decode_frame(AVCodecContext *avctx,
172 void *data, int *got_frame,
173 AVPacket *avpkt)
174 {
175 const uint8_t *buf = avpkt->data;
176 int buf_size = avpkt->size;
177 CmvContext *s = avctx->priv_data;
178 const uint8_t *buf_end = buf + buf_size;
179 AVFrame *frame = data;
180 int ret;
181
182 if (buf_end - buf < EA_PREAMBLE_SIZE)
183 return AVERROR_INVALIDDATA;
184
185 if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) {
186 unsigned size = AV_RL32(buf + 4);
187 ret = cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end);
188 if (ret < 0)
189 return ret;
190 if (size > buf_end - buf - EA_PREAMBLE_SIZE)
191 return AVERROR_INVALIDDATA;
192 buf += size;
193 }
194
195 if ((ret = av_image_check_size(s->width, s->height, 0, s->avctx)) < 0)
196 return ret;
197
198 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
199 return ret;
200
201 memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
202
203 buf += EA_PREAMBLE_SIZE;
204 if ((buf[0]&1)) { // subtype
205 cmv_decode_inter(s, frame, buf+2, buf_end);
206 frame->key_frame = 0;
207 frame->pict_type = AV_PICTURE_TYPE_P;
208 }else{
209 frame->key_frame = 1;
210 frame->pict_type = AV_PICTURE_TYPE_I;
211 cmv_decode_intra(s, frame, buf+2, buf_end);
212 }
213
214 av_frame_unref(s->last2_frame);
215 av_frame_move_ref(s->last2_frame, s->last_frame);
216 if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
217 return ret;
218
219 *got_frame = 1;
220
221 return buf_size;
222 }
223
cmv_decode_end(AVCodecContext * avctx)224 static av_cold int cmv_decode_end(AVCodecContext *avctx){
225 CmvContext *s = avctx->priv_data;
226
227 av_frame_free(&s->last_frame);
228 av_frame_free(&s->last2_frame);
229
230 return 0;
231 }
232
233 AVCodec ff_eacmv_decoder = {
234 .name = "eacmv",
235 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"),
236 .type = AVMEDIA_TYPE_VIDEO,
237 .id = AV_CODEC_ID_CMV,
238 .priv_data_size = sizeof(CmvContext),
239 .init = cmv_decode_init,
240 .close = cmv_decode_end,
241 .decode = cmv_decode_frame,
242 .capabilities = AV_CODEC_CAP_DR1,
243 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
244 };
245