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"
36 typedef struct CmvContext {
37 AVCodecContext *avctx;
38 AVFrame frame; ///< current
39 AVFrame last_frame; ///< last
40 AVFrame last2_frame; ///< second-last
42 unsigned int palette[AVPALETTE_COUNT];
45 static av_cold int cmv_decode_init(AVCodecContext *avctx){
46 CmvContext *s = avctx->priv_data;
47 avcodec_get_frame_defaults(&s->frame);
48 avcodec_get_frame_defaults(&s->last_frame);
49 avcodec_get_frame_defaults(&s->last2_frame);
52 avctx->pix_fmt = AV_PIX_FMT_PAL8;
56 static void cmv_decode_intra(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
57 unsigned char *dst = s->frame.data[0];
60 for (i=0; i < s->avctx->height && buf_end - buf >= s->avctx->width; i++) {
61 memcpy(dst, buf, s->avctx->width);
62 dst += s->frame.linesize[0];
63 buf += s->avctx->width;
67 static void cmv_motcomp(unsigned char *dst, int dst_stride,
68 const unsigned char *src, int src_stride,
70 int xoffset, int yoffset,
71 int width, int height){
77 if (i+xoffset>=0 && i+xoffset<width &&
78 j+yoffset>=0 && j+yoffset<height) {
79 dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset];
81 dst[j*dst_stride + i] = 0;
86 static void cmv_decode_inter(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
87 const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16);
91 for(y=0; y<s->avctx->height/4; y++)
92 for(x=0; x<s->avctx->width/4 && buf_end - buf > i; x++) {
94 unsigned char *dst = s->frame.data[0] + (y*4)*s->frame.linesize[0] + x*4;
95 if (raw+16<buf_end && *raw==0xFF) { /* intra */
98 memcpy(dst+s->frame.linesize[0], raw+4, 4);
99 memcpy(dst+2*s->frame.linesize[0], raw+8, 4);
100 memcpy(dst+3*s->frame.linesize[0], raw+12, 4);
102 }else if(raw<buf_end) { /* inter using second-last frame as reference */
103 int xoffset = (*raw & 0xF) - 7;
104 int yoffset = ((*raw >> 4)) - 7;
105 if (s->last2_frame.data[0])
106 cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
107 s->last2_frame.data[0], s->last2_frame.linesize[0],
108 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
111 }else{ /* inter using last frame as reference */
112 int xoffset = (buf[i] & 0xF) - 7;
113 int yoffset = ((buf[i] >> 4)) - 7;
114 if (s->last_frame.data[0])
115 cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
116 s->last_frame.data[0], s->last_frame.linesize[0],
117 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
123 static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end)
125 int pal_start, pal_count, i;
127 if(buf_end - buf < 16) {
128 av_log(s->avctx, AV_LOG_WARNING, "truncated header\n");
132 s->width = AV_RL16(&buf[4]);
133 s->height = AV_RL16(&buf[6]);
134 if (s->avctx->width!=s->width || s->avctx->height!=s->height)
135 avcodec_set_dimensions(s->avctx, s->width, s->height);
137 s->avctx->time_base.num = 1;
138 s->avctx->time_base.den = AV_RL16(&buf[10]);
140 pal_start = AV_RL16(&buf[12]);
141 pal_count = AV_RL16(&buf[14]);
144 for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
145 s->palette[i] = 0xFFU << 24 | AV_RB24(buf);
150 #define EA_PREAMBLE_SIZE 8
151 #define MVIh_TAG MKTAG('M', 'V', 'I', 'h')
153 static int cmv_decode_frame(AVCodecContext *avctx,
154 void *data, int *data_size,
157 const uint8_t *buf = avpkt->data;
158 int buf_size = avpkt->size;
159 CmvContext *s = avctx->priv_data;
160 const uint8_t *buf_end = buf + buf_size;
162 if (buf_end - buf < EA_PREAMBLE_SIZE)
163 return AVERROR_INVALIDDATA;
165 if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) {
166 unsigned size = AV_RL32(buf + 4);
167 cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end);
168 if (size > buf_end - buf - EA_PREAMBLE_SIZE)
173 if (av_image_check_size(s->width, s->height, 0, s->avctx))
177 if (s->last2_frame.data[0])
178 avctx->release_buffer(avctx, &s->last2_frame);
179 FFSWAP(AVFrame, s->last_frame, s->last2_frame);
180 FFSWAP(AVFrame, s->frame, s->last_frame);
182 s->frame.reference = 3;
183 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID |
184 FF_BUFFER_HINTS_READABLE |
185 FF_BUFFER_HINTS_PRESERVE;
186 if (avctx->get_buffer(avctx, &s->frame)<0) {
187 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
191 memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
193 buf += EA_PREAMBLE_SIZE;
194 if ((buf[0]&1)) { // subtype
195 cmv_decode_inter(s, buf+2, buf_end);
196 s->frame.key_frame = 0;
197 s->frame.pict_type = AV_PICTURE_TYPE_P;
199 s->frame.key_frame = 1;
200 s->frame.pict_type = AV_PICTURE_TYPE_I;
201 cmv_decode_intra(s, buf+2, buf_end);
204 *data_size = sizeof(AVFrame);
205 *(AVFrame*)data = s->frame;
210 static av_cold int cmv_decode_end(AVCodecContext *avctx){
211 CmvContext *s = avctx->priv_data;
212 if (s->frame.data[0])
213 s->avctx->release_buffer(avctx, &s->frame);
214 if (s->last_frame.data[0])
215 s->avctx->release_buffer(avctx, &s->last_frame);
216 if (s->last2_frame.data[0])
217 s->avctx->release_buffer(avctx, &s->last2_frame);
222 AVCodec ff_eacmv_decoder = {
224 .type = AVMEDIA_TYPE_VIDEO,
225 .id = AV_CODEC_ID_CMV,
226 .priv_data_size = sizeof(CmvContext),
227 .init = cmv_decode_init,
228 .close = cmv_decode_end,
229 .decode = cmv_decode_frame,
230 .capabilities = CODEC_CAP_DR1,
231 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"),