Libav
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00001 /* 00002 * Electronic Arts CMV Video Decoder 00003 * Copyright (c) 2007-2008 Peter Ross 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * FFmpeg is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with FFmpeg; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00031 #include "libavutil/intreadwrite.h" 00032 #include "avcodec.h" 00033 00034 typedef struct CmvContext { 00035 AVCodecContext *avctx; 00036 AVFrame frame; 00037 AVFrame last_frame; 00038 AVFrame last2_frame; 00039 int width, height; 00040 unsigned int palette[AVPALETTE_COUNT]; 00041 } CmvContext; 00042 00043 static av_cold int cmv_decode_init(AVCodecContext *avctx){ 00044 CmvContext *s = avctx->priv_data; 00045 s->avctx = avctx; 00046 avctx->pix_fmt = PIX_FMT_PAL8; 00047 return 0; 00048 } 00049 00050 static void cmv_decode_intra(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){ 00051 unsigned char *dst = s->frame.data[0]; 00052 int i; 00053 00054 for (i=0; i < s->avctx->height && buf+s->avctx->width<=buf_end; i++) { 00055 memcpy(dst, buf, s->avctx->width); 00056 dst += s->frame.linesize[0]; 00057 buf += s->avctx->width; 00058 } 00059 } 00060 00061 static void cmv_motcomp(unsigned char *dst, int dst_stride, 00062 const unsigned char *src, int src_stride, 00063 int x, int y, 00064 int xoffset, int yoffset, 00065 int width, int height){ 00066 int i,j; 00067 00068 for(j=y;j<y+4;j++) 00069 for(i=x;i<x+4;i++) 00070 { 00071 if (i+xoffset>=0 && i+xoffset<width && 00072 j+yoffset>=0 && j+yoffset<height) { 00073 dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset]; 00074 }else{ 00075 dst[j*dst_stride + i] = 0; 00076 } 00077 } 00078 } 00079 00080 static void cmv_decode_inter(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){ 00081 const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16); 00082 int x,y,i; 00083 00084 i = 0; 00085 for(y=0; y<s->avctx->height/4; y++) 00086 for(x=0; x<s->avctx->width/4 && buf+i<buf_end; x++) { 00087 if (buf[i]==0xFF) { 00088 unsigned char *dst = s->frame.data[0] + (y*4)*s->frame.linesize[0] + x*4; 00089 if (raw+16<buf_end && *raw==0xFF) { /* intra */ 00090 raw++; 00091 memcpy(dst, raw, 4); 00092 memcpy(dst+s->frame.linesize[0], raw+4, 4); 00093 memcpy(dst+2*s->frame.linesize[0], raw+8, 4); 00094 memcpy(dst+3*s->frame.linesize[0], raw+12, 4); 00095 raw+=16; 00096 }else if(raw<buf_end) { /* inter using second-last frame as reference */ 00097 int xoffset = (*raw & 0xF) - 7; 00098 int yoffset = ((*raw >> 4)) - 7; 00099 cmv_motcomp(s->frame.data[0], s->frame.linesize[0], 00100 s->last2_frame.data[0], s->last2_frame.linesize[0], 00101 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height); 00102 raw++; 00103 } 00104 }else{ /* inter using last frame as reference */ 00105 int xoffset = (buf[i] & 0xF) - 7; 00106 int yoffset = ((buf[i] >> 4)) - 7; 00107 cmv_motcomp(s->frame.data[0], s->frame.linesize[0], 00108 s->last_frame.data[0], s->last_frame.linesize[0], 00109 x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height); 00110 } 00111 i++; 00112 } 00113 } 00114 00115 static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end) 00116 { 00117 int pal_start, pal_count, i; 00118 00119 if(buf+16>=buf_end) { 00120 av_log(s->avctx, AV_LOG_WARNING, "truncated header\n"); 00121 return; 00122 } 00123 00124 s->width = AV_RL16(&buf[4]); 00125 s->height = AV_RL16(&buf[6]); 00126 if (s->avctx->width!=s->width || s->avctx->height!=s->height) 00127 avcodec_set_dimensions(s->avctx, s->width, s->height); 00128 00129 s->avctx->time_base.num = 1; 00130 s->avctx->time_base.den = AV_RL16(&buf[10]); 00131 00132 pal_start = AV_RL16(&buf[12]); 00133 pal_count = AV_RL16(&buf[14]); 00134 00135 buf += 16; 00136 for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf+2<buf_end; i++) { 00137 s->palette[i] = AV_RB24(buf); 00138 buf += 3; 00139 } 00140 } 00141 00142 #define EA_PREAMBLE_SIZE 8 00143 #define MVIh_TAG MKTAG('M', 'V', 'I', 'h') 00144 00145 static int cmv_decode_frame(AVCodecContext *avctx, 00146 void *data, int *data_size, 00147 AVPacket *avpkt) 00148 { 00149 const uint8_t *buf = avpkt->data; 00150 int buf_size = avpkt->size; 00151 CmvContext *s = avctx->priv_data; 00152 const uint8_t *buf_end = buf + buf_size; 00153 00154 if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) { 00155 cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end); 00156 return buf_size; 00157 } 00158 00159 if (avcodec_check_dimensions(s->avctx, s->width, s->height)) 00160 return -1; 00161 00162 /* shuffle */ 00163 if (s->last2_frame.data[0]) 00164 avctx->release_buffer(avctx, &s->last2_frame); 00165 FFSWAP(AVFrame, s->last_frame, s->last2_frame); 00166 FFSWAP(AVFrame, s->frame, s->last_frame); 00167 00168 s->frame.reference = 1; 00169 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID; 00170 if (avctx->get_buffer(avctx, &s->frame)<0) { 00171 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00172 return -1; 00173 } 00174 00175 memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE); 00176 00177 buf += EA_PREAMBLE_SIZE; 00178 if ((buf[0]&1)) { // subtype 00179 cmv_decode_inter(s, buf+2, buf_end); 00180 s->frame.key_frame = 0; 00181 s->frame.pict_type = FF_P_TYPE; 00182 }else{ 00183 s->frame.key_frame = 1; 00184 s->frame.pict_type = FF_I_TYPE; 00185 cmv_decode_intra(s, buf+2, buf_end); 00186 } 00187 00188 *data_size = sizeof(AVFrame); 00189 *(AVFrame*)data = s->frame; 00190 00191 return buf_size; 00192 } 00193 00194 static av_cold int cmv_decode_end(AVCodecContext *avctx){ 00195 CmvContext *s = avctx->priv_data; 00196 if (s->frame.data[0]) 00197 s->avctx->release_buffer(avctx, &s->frame); 00198 if (s->last_frame.data[0]) 00199 s->avctx->release_buffer(avctx, &s->last_frame); 00200 if (s->last2_frame.data[0]) 00201 s->avctx->release_buffer(avctx, &s->last2_frame); 00202 00203 return 0; 00204 } 00205 00206 AVCodec eacmv_decoder = { 00207 "eacmv", 00208 AVMEDIA_TYPE_VIDEO, 00209 CODEC_ID_CMV, 00210 sizeof(CmvContext), 00211 cmv_decode_init, 00212 NULL, 00213 cmv_decode_end, 00214 cmv_decode_frame, 00215 CODEC_CAP_DR1, 00216 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"), 00217 };