2 * Electronic Arts CMV Video Decoder
3 * Copyright (c) 2007-2008 Peter Ross
5 * This file is part of FFmpeg.
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.
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.
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
24 * Electronic Arts CMV Video Decoder
25 * by Peter Ross (pross@xvid.org)
27 * Technical details here:
28 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_CMV
31 #include "libavutil/common.h"
32 #include "libavutil/intreadwrite.h"
33 #include "libavutil/imgutils.h"
37 typedef struct CmvContext {
38 AVCodecContext *avctx;
39 AVFrame frame; ///< current
40 AVFrame last_frame; ///< last
41 AVFrame last2_frame; ///< second-last
43 unsigned int palette[AVPALETTE_COUNT];
46 static av_cold int cmv_decode_init(AVCodecContext *avctx){
47 CmvContext *s = avctx->priv_data;
48 avcodec_get_frame_defaults(&s->frame);
49 avcodec_get_frame_defaults(&s->last_frame);
50 avcodec_get_frame_defaults(&s->last2_frame);
53 avctx->pix_fmt = AV_PIX_FMT_PAL8;
57 static void cmv_decode_intra(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
58 unsigned char *dst = s->frame.data[0];
61 for (i=0; i < s->avctx->height && buf_end - buf >= s->avctx->width; i++) {
62 memcpy(dst, buf, s->avctx->width);
63 dst += s->frame.linesize[0];
64 buf += s->avctx->width;
68 static void cmv_motcomp(unsigned char *dst, int dst_stride,
69 const unsigned char *src, int src_stride,
71 int xoffset, int yoffset,
72 int width, int height){
78 if (i+xoffset>=0 && i+xoffset<width &&
79 j+yoffset>=0 && j+yoffset<height) {
80 dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset];
82 dst[j*dst_stride + i] = 0;
87 static void cmv_decode_inter(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
88 const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16);
92 for(y=0; y<s->avctx->height/4; y++)
93 for(x=0; x<s->avctx->width/4 && buf_end - buf > i; x++) {
95 unsigned char *dst = s->frame.data[0] + (y*4)*s->frame.linesize[0] + x*4;
96 if (raw+16<buf_end && *raw==0xFF) { /* intra */
99 memcpy(dst+s->frame.linesize[0], raw+4, 4);
100 memcpy(dst+2*s->frame.linesize[0], raw+8, 4);
101 memcpy(dst+3*s->frame.linesize[0], raw+12, 4);
103 }else if(raw<buf_end) { /* inter using second-last frame as reference */
104 int xoffset = (*raw & 0xF) - 7;
105 int yoffset = ((*raw >> 4)) - 7;
106 if (s->last2_frame.data[0])
107 cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
108 s->last2_frame.data[0], s->last2_frame.linesize[0],
109 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
112 }else{ /* inter using last frame as reference */
113 int xoffset = (buf[i] & 0xF) - 7;
114 int yoffset = ((buf[i] >> 4)) - 7;
115 if (s->last_frame.data[0])
116 cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
117 s->last_frame.data[0], s->last_frame.linesize[0],
118 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
124 static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end)
126 int pal_start, pal_count, i;
128 if(buf_end - buf < 16) {
129 av_log(s->avctx, AV_LOG_WARNING, "truncated header\n");
133 s->width = AV_RL16(&buf[4]);
134 s->height = AV_RL16(&buf[6]);
135 if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
136 avcodec_set_dimensions(s->avctx, s->width, s->height);
137 if (s->frame.data[0])
138 s->avctx->release_buffer(s->avctx, &s->frame);
139 if (s->last_frame.data[0])
140 s->avctx->release_buffer(s->avctx, &s->last_frame);
143 s->avctx->time_base.num = 1;
144 s->avctx->time_base.den = AV_RL16(&buf[10]);
146 pal_start = AV_RL16(&buf[12]);
147 pal_count = AV_RL16(&buf[14]);
150 for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
151 s->palette[i] = 0xFFU << 24 | AV_RB24(buf);
156 #define EA_PREAMBLE_SIZE 8
157 #define MVIh_TAG MKTAG('M', 'V', 'I', 'h')
159 static int cmv_decode_frame(AVCodecContext *avctx,
160 void *data, int *got_frame,
163 const uint8_t *buf = avpkt->data;
164 int buf_size = avpkt->size;
165 CmvContext *s = avctx->priv_data;
166 const uint8_t *buf_end = buf + buf_size;
168 if (buf_end - buf < EA_PREAMBLE_SIZE)
169 return AVERROR_INVALIDDATA;
171 if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) {
172 unsigned size = AV_RL32(buf + 4);
173 cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end);
174 if (size > buf_end - buf - EA_PREAMBLE_SIZE)
179 if (av_image_check_size(s->width, s->height, 0, s->avctx))
183 if (s->last2_frame.data[0])
184 avctx->release_buffer(avctx, &s->last2_frame);
185 FFSWAP(AVFrame, s->last_frame, s->last2_frame);
186 FFSWAP(AVFrame, s->frame, s->last_frame);
188 s->frame.reference = 3;
189 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID |
190 FF_BUFFER_HINTS_READABLE |
191 FF_BUFFER_HINTS_PRESERVE;
192 if (ff_get_buffer(avctx, &s->frame)<0) {
193 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
197 memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
199 buf += EA_PREAMBLE_SIZE;
200 if ((buf[0]&1)) { // subtype
201 cmv_decode_inter(s, buf+2, buf_end);
202 s->frame.key_frame = 0;
203 s->frame.pict_type = AV_PICTURE_TYPE_P;
205 s->frame.key_frame = 1;
206 s->frame.pict_type = AV_PICTURE_TYPE_I;
207 cmv_decode_intra(s, buf+2, buf_end);
211 *(AVFrame*)data = s->frame;
216 static av_cold int cmv_decode_end(AVCodecContext *avctx){
217 CmvContext *s = avctx->priv_data;
218 if (s->frame.data[0])
219 s->avctx->release_buffer(avctx, &s->frame);
220 if (s->last_frame.data[0])
221 s->avctx->release_buffer(avctx, &s->last_frame);
222 if (s->last2_frame.data[0])
223 s->avctx->release_buffer(avctx, &s->last2_frame);
228 AVCodec ff_eacmv_decoder = {
230 .type = AVMEDIA_TYPE_VIDEO,
231 .id = AV_CODEC_ID_CMV,
232 .priv_data_size = sizeof(CmvContext),
233 .init = cmv_decode_init,
234 .close = cmv_decode_end,
235 .decode = cmv_decode_frame,
236 .capabilities = CODEC_CAP_DR1,
237 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"),