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 "codec_internal.h"
36 #include "internal.h"
37
38 typedef struct CmvContext {
39 AVCodecContext *avctx;
40 AVFrame *last_frame; ///< last
41 AVFrame *last2_frame; ///< second-last
42 int width, height;
43 unsigned int palette[AVPALETTE_COUNT];
44 } CmvContext;
45
cmv_decode_init(AVCodecContext *avctx)46 static av_cold int cmv_decode_init(AVCodecContext *avctx){
47 CmvContext *s = avctx->priv_data;
48
49 s->avctx = avctx;
50 avctx->pix_fmt = AV_PIX_FMT_PAL8;
51
52 s->last_frame = av_frame_alloc();
53 s->last2_frame = av_frame_alloc();
54 if (!s->last_frame || !s->last2_frame)
55 return AVERROR(ENOMEM);
56
57 return 0;
58 }
59
cmv_decode_intra(CmvContext * s, AVFrame *frame, const uint8_t *buf, const uint8_t *buf_end)60 static void cmv_decode_intra(CmvContext * s, AVFrame *frame,
61 const uint8_t *buf, const uint8_t *buf_end)
62 {
63 unsigned char *dst = frame->data[0];
64 int i;
65
66 for (i=0; i < s->avctx->height && buf_end - buf >= s->avctx->width; i++) {
67 memcpy(dst, buf, s->avctx->width);
68 dst += frame->linesize[0];
69 buf += s->avctx->width;
70 }
71 }
72
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)73 static void cmv_motcomp(unsigned char *dst, ptrdiff_t dst_stride,
74 const unsigned char *src, ptrdiff_t src_stride,
75 int x, int y,
76 int xoffset, int yoffset,
77 int width, int height){
78 int i,j;
79
80 for(j=y;j<y+4;j++)
81 for(i=x;i<x+4;i++)
82 {
83 if (i+xoffset>=0 && i+xoffset<width &&
84 j+yoffset>=0 && j+yoffset<height) {
85 dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset];
86 }else{
87 dst[j*dst_stride + i] = 0;
88 }
89 }
90 }
91
cmv_decode_inter(CmvContext *s, AVFrame *frame, const uint8_t *buf, const uint8_t *buf_end)92 static void cmv_decode_inter(CmvContext *s, AVFrame *frame, const uint8_t *buf,
93 const uint8_t *buf_end)
94 {
95 const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16);
96 int x,y,i;
97
98 i = 0;
99 for(y=0; y<s->avctx->height/4; y++)
100 for(x=0; x<s->avctx->width/4 && buf_end - buf > i; x++) {
101 if (buf[i]==0xFF) {
102 unsigned char *dst = frame->data[0] + (y*4)*frame->linesize[0] + x*4;
103 if (raw+16<buf_end && *raw==0xFF) { /* intra */
104 raw++;
105 memcpy(dst, raw, 4);
106 memcpy(dst + frame->linesize[0], raw+4, 4);
107 memcpy(dst + 2 * frame->linesize[0], raw+8, 4);
108 memcpy(dst + 3 * frame->linesize[0], raw+12, 4);
109 raw+=16;
110 }else if(raw<buf_end) { /* inter using second-last frame as reference */
111 int xoffset = (*raw & 0xF) - 7;
112 int yoffset = ((*raw >> 4)) - 7;
113 if (s->last2_frame->data[0])
114 cmv_motcomp(frame->data[0], frame->linesize[0],
115 s->last2_frame->data[0], s->last2_frame->linesize[0],
116 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
117 raw++;
118 }
119 }else{ /* inter using last frame as reference */
120 int xoffset = (buf[i] & 0xF) - 7;
121 int yoffset = ((buf[i] >> 4)) - 7;
122 if (s->last_frame->data[0])
123 cmv_motcomp(frame->data[0], frame->linesize[0],
124 s->last_frame->data[0], s->last_frame->linesize[0],
125 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
126 }
127 i++;
128 }
129 }
130
cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end)131 static int cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end)
132 {
133 int pal_start, pal_count, i, ret, fps;
134
135 if(buf_end - buf < 16) {
136 av_log(s->avctx, AV_LOG_WARNING, "truncated header\n");
137 return AVERROR_INVALIDDATA;
138 }
139
140 s->width = AV_RL16(&buf[4]);
141 s->height = AV_RL16(&buf[6]);
142
143 if (s->width != s->avctx->width ||
144 s->height != s->avctx->height) {
145 av_frame_unref(s->last_frame);
146 av_frame_unref(s->last2_frame);
147 }
148
149 ret = ff_set_dimensions(s->avctx, s->width, s->height);
150 if (ret < 0)
151 return ret;
152
153 fps = AV_RL16(&buf[10]);
154 if (fps > 0)
155 s->avctx->framerate = (AVRational){ fps, 1 };
156
157 pal_start = AV_RL16(&buf[12]);
158 pal_count = AV_RL16(&buf[14]);
159
160 buf += 16;
161 for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
162 s->palette[i] = 0xFFU << 24 | AV_RB24(buf);
163 buf += 3;
164 }
165
166 return 0;
167 }
168
169 #define EA_PREAMBLE_SIZE 8
170 #define MVIh_TAG MKTAG('M', 'V', 'I', 'h')
171
cmv_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)172 static int cmv_decode_frame(AVCodecContext *avctx, AVFrame *frame,
173 int *got_frame, 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 int ret;
180
181 if (buf_end - buf < EA_PREAMBLE_SIZE)
182 return AVERROR_INVALIDDATA;
183
184 if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) {
185 unsigned size = AV_RL32(buf + 4);
186 ret = cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end);
187 if (ret < 0)
188 return ret;
189 if (size > buf_end - buf - EA_PREAMBLE_SIZE)
190 return AVERROR_INVALIDDATA;
191 buf += size;
192 }
193
194 if ((ret = av_image_check_size(s->width, s->height, 0, s->avctx)) < 0)
195 return ret;
196
197 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
198 return ret;
199
200 memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
201
202 buf += EA_PREAMBLE_SIZE;
203 if ((buf[0]&1)) { // subtype
204 cmv_decode_inter(s, frame, buf+2, buf_end);
205 frame->key_frame = 0;
206 frame->pict_type = AV_PICTURE_TYPE_P;
207 }else{
208 frame->key_frame = 1;
209 frame->pict_type = AV_PICTURE_TYPE_I;
210 cmv_decode_intra(s, frame, buf+2, buf_end);
211 }
212
213 av_frame_unref(s->last2_frame);
214 av_frame_move_ref(s->last2_frame, s->last_frame);
215 if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
216 return ret;
217
218 *got_frame = 1;
219
220 return buf_size;
221 }
222
cmv_decode_end(AVCodecContext *avctx)223 static av_cold int cmv_decode_end(AVCodecContext *avctx){
224 CmvContext *s = avctx->priv_data;
225
226 av_frame_free(&s->last_frame);
227 av_frame_free(&s->last2_frame);
228
229 return 0;
230 }
231
232 const FFCodec ff_eacmv_decoder = {
233 .p.name = "eacmv",
234 .p.long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"),
235 .p.type = AVMEDIA_TYPE_VIDEO,
236 .p.id = AV_CODEC_ID_CMV,
237 .priv_data_size = sizeof(CmvContext),
238 .init = cmv_decode_init,
239 .close = cmv_decode_end,
240 FF_CODEC_DECODE_CB(cmv_decode_frame),
241 .p.capabilities = AV_CODEC_CAP_DR1,
242 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
243 };
244