/* * Electronic Arts CMV Video Decoder * Copyright (c) 2007-2008 Peter Ross * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * Electronic Arts CMV Video Decoder * by Peter Ross (pross@xvid.org) * * Technical details here: * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_CMV */ #include "libavutil/intreadwrite.h" #include "avcodec.h" typedef struct CmvContext { AVCodecContext *avctx; AVFrame frame; ///< current AVFrame last_frame; ///< last AVFrame last2_frame; ///< second-last int width, height; unsigned int palette[AVPALETTE_COUNT]; } CmvContext; static av_cold int cmv_decode_init(AVCodecContext *avctx){ CmvContext *s = avctx->priv_data; s->avctx = avctx; avctx->pix_fmt = PIX_FMT_PAL8; return 0; } static void cmv_decode_intra(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){ unsigned char *dst = s->frame.data[0]; int i; for (i=0; i < s->avctx->height && buf+s->avctx->width<=buf_end; i++) { memcpy(dst, buf, s->avctx->width); dst += s->frame.linesize[0]; buf += s->avctx->width; } } static void cmv_motcomp(unsigned char *dst, int dst_stride, const unsigned char *src, int src_stride, int x, int y, int xoffset, int yoffset, int width, int height){ int i,j; for(j=y;j<y+4;j++) for(i=x;i<x+4;i++) { if (i+xoffset>=0 && i+xoffset<width && j+yoffset>=0 && j+yoffset<height) { dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset]; }else{ dst[j*dst_stride + i] = 0; } } } static void cmv_decode_inter(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){ const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16); int x,y,i; i = 0; for(y=0; y<s->avctx->height/4; y++) for(x=0; x<s->avctx->width/4 && buf+i<buf_end; x++) { if (buf[i]==0xFF) { unsigned char *dst = s->frame.data[0] + (y*4)*s->frame.linesize[0] + x*4; if (raw+16<buf_end && *raw==0xFF) { /* intra */ raw++; memcpy(dst, raw, 4); memcpy(dst+s->frame.linesize[0], raw+4, 4); memcpy(dst+2*s->frame.linesize[0], raw+8, 4); memcpy(dst+3*s->frame.linesize[0], raw+12, 4); raw+=16; }else if(raw<buf_end) { /* inter using second-last frame as reference */ int xoffset = (*raw & 0xF) - 7; int yoffset = ((*raw >> 4)) - 7; cmv_motcomp(s->frame.data[0], s->frame.linesize[0], s->last2_frame.data[0], s->last2_frame.linesize[0], x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height); raw++; } }else{ /* inter using last frame as reference */ int xoffset = (buf[i] & 0xF) - 7; int yoffset = ((buf[i] >> 4)) - 7; cmv_motcomp(s->frame.data[0], s->frame.linesize[0], s->last_frame.data[0], s->last_frame.linesize[0], x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height); } i++; } } static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end) { int pal_start, pal_count, i; if(buf+16>=buf_end) { av_log(s->avctx, AV_LOG_WARNING, "truncated header\n"); return; } s->width = AV_RL16(&buf[4]); s->height = AV_RL16(&buf[6]); if (s->avctx->width!=s->width || s->avctx->height!=s->height) avcodec_set_dimensions(s->avctx, s->width, s->height); s->avctx->time_base.num = 1; s->avctx->time_base.den = AV_RL16(&buf[10]); pal_start = AV_RL16(&buf[12]); pal_count = AV_RL16(&buf[14]); buf += 16; for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf+2<buf_end; i++) { s->palette[i] = AV_RB24(buf); buf += 3; } } #define EA_PREAMBLE_SIZE 8 #define MVIh_TAG MKTAG('M', 'V', 'I', 'h') static int cmv_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; CmvContext *s = avctx->priv_data; const uint8_t *buf_end = buf + buf_size; if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) { cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end); return buf_size; } if (avcodec_check_dimensions(s->avctx, s->width, s->height)) return -1; /* shuffle */ if (s->last2_frame.data[0]) avctx->release_buffer(avctx, &s->last2_frame); FFSWAP(AVFrame, s->last_frame, s->last2_frame); FFSWAP(AVFrame, s->frame, s->last_frame); s->frame.reference = 1; s->frame.buffer_hints = FF_BUFFER_HINTS_VALID; if (avctx->get_buffer(avctx, &s->frame)<0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return -1; } memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE); buf += EA_PREAMBLE_SIZE; if ((buf[0]&1)) { // subtype cmv_decode_inter(s, buf+2, buf_end); s->frame.key_frame = 0; s->frame.pict_type = FF_P_TYPE; }else{ s->frame.key_frame = 1; s->frame.pict_type = FF_I_TYPE; cmv_decode_intra(s, buf+2, buf_end); } *data_size = sizeof(AVFrame); *(AVFrame*)data = s->frame; return buf_size; } static av_cold int cmv_decode_end(AVCodecContext *avctx){ CmvContext *s = avctx->priv_data; if (s->frame.data[0]) s->avctx->release_buffer(avctx, &s->frame); if (s->last_frame.data[0]) s->avctx->release_buffer(avctx, &s->last_frame); if (s->last2_frame.data[0]) s->avctx->release_buffer(avctx, &s->last2_frame); return 0; } AVCodec eacmv_decoder = { "eacmv", AVMEDIA_TYPE_VIDEO, CODEC_ID_CMV, sizeof(CmvContext), cmv_decode_init, NULL, cmv_decode_end, cmv_decode_frame, CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"), };