| 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 "internal.h" |
| 36 | |
| 37 | typedef struct CmvContext { |
| 38 | AVCodecContext *avctx; |
| 39 | AVFrame *last_frame; ///< last |
| 40 | AVFrame *last2_frame; ///< second-last |
| 41 | int width, height; |
| 42 | unsigned int palette[AVPALETTE_COUNT]; |
| 43 | } CmvContext; |
| 44 | |
| 45 | static av_cold int cmv_decode_init(AVCodecContext *avctx){ |
| 46 | CmvContext *s = avctx->priv_data; |
| 47 | |
| 48 | s->avctx = avctx; |
| 49 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| 50 | |
| 51 | s->last_frame = av_frame_alloc(); |
| 52 | s->last2_frame = av_frame_alloc(); |
| 53 | if (!s->last_frame || !s->last2_frame) { |
| 54 | av_frame_free(&s->last_frame); |
| 55 | av_frame_free(&s->last2_frame); |
| 56 | return AVERROR(ENOMEM); |
| 57 | } |
| 58 | |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | static void cmv_decode_intra(CmvContext * s, AVFrame *frame, |
| 63 | const uint8_t *buf, const uint8_t *buf_end) |
| 64 | { |
| 65 | unsigned char *dst = frame->data[0]; |
| 66 | int i; |
| 67 | |
| 68 | for (i=0; i < s->avctx->height && buf_end - buf >= s->avctx->width; i++) { |
| 69 | memcpy(dst, buf, s->avctx->width); |
| 70 | dst += frame->linesize[0]; |
| 71 | buf += s->avctx->width; |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | static void cmv_motcomp(unsigned char *dst, int dst_stride, |
| 76 | const unsigned char *src, int src_stride, |
| 77 | int x, int y, |
| 78 | int xoffset, int yoffset, |
| 79 | int width, int height){ |
| 80 | int i,j; |
| 81 | |
| 82 | for(j=y;j<y+4;j++) |
| 83 | for(i=x;i<x+4;i++) |
| 84 | { |
| 85 | if (i+xoffset>=0 && i+xoffset<width && |
| 86 | j+yoffset>=0 && j+yoffset<height) { |
| 87 | dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset]; |
| 88 | }else{ |
| 89 | dst[j*dst_stride + i] = 0; |
| 90 | } |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | static void cmv_decode_inter(CmvContext *s, AVFrame *frame, const uint8_t *buf, |
| 95 | const uint8_t *buf_end) |
| 96 | { |
| 97 | const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16); |
| 98 | int x,y,i; |
| 99 | |
| 100 | i = 0; |
| 101 | for(y=0; y<s->avctx->height/4; y++) |
| 102 | for(x=0; x<s->avctx->width/4 && buf_end - buf > i; x++) { |
| 103 | if (buf[i]==0xFF) { |
| 104 | unsigned char *dst = frame->data[0] + (y*4)*frame->linesize[0] + x*4; |
| 105 | if (raw+16<buf_end && *raw==0xFF) { /* intra */ |
| 106 | raw++; |
| 107 | memcpy(dst, raw, 4); |
| 108 | memcpy(dst + frame->linesize[0], raw+4, 4); |
| 109 | memcpy(dst + 2 * frame->linesize[0], raw+8, 4); |
| 110 | memcpy(dst + 3 * frame->linesize[0], raw+12, 4); |
| 111 | raw+=16; |
| 112 | }else if(raw<buf_end) { /* inter using second-last frame as reference */ |
| 113 | int xoffset = (*raw & 0xF) - 7; |
| 114 | int yoffset = ((*raw >> 4)) - 7; |
| 115 | if (s->last2_frame->data[0]) |
| 116 | cmv_motcomp(frame->data[0], frame->linesize[0], |
| 117 | s->last2_frame->data[0], s->last2_frame->linesize[0], |
| 118 | x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height); |
| 119 | raw++; |
| 120 | } |
| 121 | }else{ /* inter using last frame as reference */ |
| 122 | int xoffset = (buf[i] & 0xF) - 7; |
| 123 | int yoffset = ((buf[i] >> 4)) - 7; |
| 124 | if (s->last_frame->data[0]) |
| 125 | cmv_motcomp(frame->data[0], frame->linesize[0], |
| 126 | s->last_frame->data[0], s->last_frame->linesize[0], |
| 127 | x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height); |
| 128 | } |
| 129 | i++; |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | static int cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end) |
| 134 | { |
| 135 | int pal_start, pal_count, i, ret, fps; |
| 136 | |
| 137 | if(buf_end - buf < 16) { |
| 138 | av_log(s->avctx, AV_LOG_WARNING, "truncated header\n"); |
| 139 | return AVERROR_INVALIDDATA; |
| 140 | } |
| 141 | |
| 142 | s->width = AV_RL16(&buf[4]); |
| 143 | s->height = AV_RL16(&buf[6]); |
| 144 | |
| 145 | if (s->width != s->avctx->width || |
| 146 | s->height != s->avctx->height) { |
| 147 | av_frame_unref(s->last_frame); |
| 148 | av_frame_unref(s->last2_frame); |
| 149 | } |
| 150 | |
| 151 | ret = ff_set_dimensions(s->avctx, s->width, s->height); |
| 152 | if (ret < 0) |
| 153 | return ret; |
| 154 | |
| 155 | fps = AV_RL16(&buf[10]); |
| 156 | if (fps > 0) |
| 157 | s->avctx->time_base = (AVRational){ 1, fps }; |
| 158 | |
| 159 | pal_start = AV_RL16(&buf[12]); |
| 160 | pal_count = AV_RL16(&buf[14]); |
| 161 | |
| 162 | buf += 16; |
| 163 | for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf_end - buf >= 3; i++) { |
| 164 | s->palette[i] = 0xFFU << 24 | AV_RB24(buf); |
| 165 | buf += 3; |
| 166 | } |
| 167 | |
| 168 | return 0; |
| 169 | } |
| 170 | |
| 171 | #define EA_PREAMBLE_SIZE 8 |
| 172 | #define MVIh_TAG MKTAG('M', 'V', 'I', 'h') |
| 173 | |
| 174 | static int cmv_decode_frame(AVCodecContext *avctx, |
| 175 | void *data, int *got_frame, |
| 176 | AVPacket *avpkt) |
| 177 | { |
| 178 | const uint8_t *buf = avpkt->data; |
| 179 | int buf_size = avpkt->size; |
| 180 | CmvContext *s = avctx->priv_data; |
| 181 | const uint8_t *buf_end = buf + buf_size; |
| 182 | AVFrame *frame = data; |
| 183 | int ret; |
| 184 | |
| 185 | if (buf_end - buf < EA_PREAMBLE_SIZE) |
| 186 | return AVERROR_INVALIDDATA; |
| 187 | |
| 188 | if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) { |
| 189 | unsigned size = AV_RL32(buf + 4); |
| 190 | ret = cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end); |
| 191 | if (ret < 0) |
| 192 | return ret; |
| 193 | if (size > buf_end - buf - EA_PREAMBLE_SIZE) |
| 194 | return -1; |
| 195 | buf += size; |
| 196 | } |
| 197 | |
| 198 | if (av_image_check_size(s->width, s->height, 0, s->avctx)) |
| 199 | return -1; |
| 200 | |
| 201 | if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) |
| 202 | return ret; |
| 203 | |
| 204 | memcpy(frame->data[1], s->palette, AVPALETTE_SIZE); |
| 205 | |
| 206 | buf += EA_PREAMBLE_SIZE; |
| 207 | if ((buf[0]&1)) { // subtype |
| 208 | cmv_decode_inter(s, frame, buf+2, buf_end); |
| 209 | frame->key_frame = 0; |
| 210 | frame->pict_type = AV_PICTURE_TYPE_P; |
| 211 | }else{ |
| 212 | frame->key_frame = 1; |
| 213 | frame->pict_type = AV_PICTURE_TYPE_I; |
| 214 | cmv_decode_intra(s, frame, buf+2, buf_end); |
| 215 | } |
| 216 | |
| 217 | av_frame_unref(s->last2_frame); |
| 218 | av_frame_move_ref(s->last2_frame, s->last_frame); |
| 219 | if ((ret = av_frame_ref(s->last_frame, frame)) < 0) |
| 220 | return ret; |
| 221 | |
| 222 | *got_frame = 1; |
| 223 | |
| 224 | return buf_size; |
| 225 | } |
| 226 | |
| 227 | static av_cold int cmv_decode_end(AVCodecContext *avctx){ |
| 228 | CmvContext *s = avctx->priv_data; |
| 229 | |
| 230 | av_frame_free(&s->last_frame); |
| 231 | av_frame_free(&s->last2_frame); |
| 232 | |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | AVCodec ff_eacmv_decoder = { |
| 237 | .name = "eacmv", |
| 238 | .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"), |
| 239 | .type = AVMEDIA_TYPE_VIDEO, |
| 240 | .id = AV_CODEC_ID_CMV, |
| 241 | .priv_data_size = sizeof(CmvContext), |
| 242 | .init = cmv_decode_init, |
| 243 | .close = cmv_decode_end, |
| 244 | .decode = cmv_decode_frame, |
| 245 | .capabilities = CODEC_CAP_DR1, |
| 246 | }; |