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/intreadwrite.h" 32#include "avcodec.h" 33 34typedef struct CmvContext { 35 AVCodecContext *avctx; 36 AVFrame frame; ///< current 37 AVFrame last_frame; ///< last 38 AVFrame last2_frame; ///< second-last 39 int width, height; 40 unsigned int palette[AVPALETTE_COUNT]; 41} CmvContext; 42 43static av_cold int cmv_decode_init(AVCodecContext *avctx){ 44 CmvContext *s = avctx->priv_data; 45 s->avctx = avctx; 46 avctx->pix_fmt = PIX_FMT_PAL8; 47 return 0; 48} 49 50static void cmv_decode_intra(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){ 51 unsigned char *dst = s->frame.data[0]; 52 int i; 53 54 for (i=0; i < s->avctx->height && buf+s->avctx->width<=buf_end; i++) { 55 memcpy(dst, buf, s->avctx->width); 56 dst += s->frame.linesize[0]; 57 buf += s->avctx->width; 58 } 59} 60 61static void cmv_motcomp(unsigned char *dst, int dst_stride, 62 const unsigned char *src, int src_stride, 63 int x, int y, 64 int xoffset, int yoffset, 65 int width, int height){ 66 int i,j; 67 68 for(j=y;j<y+4;j++) 69 for(i=x;i<x+4;i++) 70 { 71 if (i+xoffset>=0 && i+xoffset<width && 72 j+yoffset>=0 && j+yoffset<height) { 73 dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset]; 74 }else{ 75 dst[j*dst_stride + i] = 0; 76 } 77 } 78} 79 80static void cmv_decode_inter(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){ 81 const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16); 82 int x,y,i; 83 84 i = 0; 85 for(y=0; y<s->avctx->height/4; y++) 86 for(x=0; x<s->avctx->width/4 && buf+i<buf_end; x++) { 87 if (buf[i]==0xFF) { 88 unsigned char *dst = s->frame.data[0] + (y*4)*s->frame.linesize[0] + x*4; 89 if (raw+16<buf_end && *raw==0xFF) { /* intra */ 90 raw++; 91 memcpy(dst, raw, 4); 92 memcpy(dst+s->frame.linesize[0], raw+4, 4); 93 memcpy(dst+2*s->frame.linesize[0], raw+8, 4); 94 memcpy(dst+3*s->frame.linesize[0], raw+12, 4); 95 raw+=16; 96 }else if(raw<buf_end) { /* inter using second-last frame as reference */ 97 int xoffset = (*raw & 0xF) - 7; 98 int yoffset = ((*raw >> 4)) - 7; 99 cmv_motcomp(s->frame.data[0], s->frame.linesize[0], 100 s->last2_frame.data[0], s->last2_frame.linesize[0], 101 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height); 102 raw++; 103 } 104 }else{ /* inter using last frame as reference */ 105 int xoffset = (buf[i] & 0xF) - 7; 106 int yoffset = ((buf[i] >> 4)) - 7; 107 cmv_motcomp(s->frame.data[0], s->frame.linesize[0], 108 s->last_frame.data[0], s->last_frame.linesize[0], 109 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height); 110 } 111 i++; 112 } 113} 114 115static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end) 116{ 117 int pal_start, pal_count, i; 118 119 if(buf+16>=buf_end) { 120 av_log(s->avctx, AV_LOG_WARNING, "truncated header\n"); 121 return; 122 } 123 124 s->width = AV_RL16(&buf[4]); 125 s->height = AV_RL16(&buf[6]); 126 if (s->avctx->width!=s->width || s->avctx->height!=s->height) 127 avcodec_set_dimensions(s->avctx, s->width, s->height); 128 129 s->avctx->time_base.num = 1; 130 s->avctx->time_base.den = AV_RL16(&buf[10]); 131 132 pal_start = AV_RL16(&buf[12]); 133 pal_count = AV_RL16(&buf[14]); 134 135 buf += 16; 136 for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf+2<buf_end; i++) { 137 s->palette[i] = AV_RB24(buf); 138 buf += 3; 139 } 140} 141 142#define EA_PREAMBLE_SIZE 8 143#define MVIh_TAG MKTAG('M', 'V', 'I', 'h') 144 145static int cmv_decode_frame(AVCodecContext *avctx, 146 void *data, int *data_size, 147 AVPacket *avpkt) 148{ 149 const uint8_t *buf = avpkt->data; 150 int buf_size = avpkt->size; 151 CmvContext *s = avctx->priv_data; 152 const uint8_t *buf_end = buf + buf_size; 153 154 if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) { 155 cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end); 156 return buf_size; 157 } 158 159 if (avcodec_check_dimensions(s->avctx, s->width, s->height)) 160 return -1; 161 162 /* shuffle */ 163 if (s->last2_frame.data[0]) 164 avctx->release_buffer(avctx, &s->last2_frame); 165 FFSWAP(AVFrame, s->last_frame, s->last2_frame); 166 FFSWAP(AVFrame, s->frame, s->last_frame); 167 168 s->frame.reference = 1; 169 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID; 170 if (avctx->get_buffer(avctx, &s->frame)<0) { 171 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 172 return -1; 173 } 174 175 memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE); 176 177 buf += EA_PREAMBLE_SIZE; 178 if ((buf[0]&1)) { // subtype 179 cmv_decode_inter(s, buf+2, buf_end); 180 s->frame.key_frame = 0; 181 s->frame.pict_type = FF_P_TYPE; 182 }else{ 183 s->frame.key_frame = 1; 184 s->frame.pict_type = FF_I_TYPE; 185 cmv_decode_intra(s, buf+2, buf_end); 186 } 187 188 *data_size = sizeof(AVFrame); 189 *(AVFrame*)data = s->frame; 190 191 return buf_size; 192} 193 194static av_cold int cmv_decode_end(AVCodecContext *avctx){ 195 CmvContext *s = avctx->priv_data; 196 if (s->frame.data[0]) 197 s->avctx->release_buffer(avctx, &s->frame); 198 if (s->last_frame.data[0]) 199 s->avctx->release_buffer(avctx, &s->last_frame); 200 if (s->last2_frame.data[0]) 201 s->avctx->release_buffer(avctx, &s->last2_frame); 202 203 return 0; 204} 205 206AVCodec eacmv_decoder = { 207 "eacmv", 208 AVMEDIA_TYPE_VIDEO, 209 CODEC_ID_CMV, 210 sizeof(CmvContext), 211 cmv_decode_init, 212 NULL, 213 cmv_decode_end, 214 cmv_decode_frame, 215 CODEC_CAP_DR1, 216 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"), 217}; 218