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libavcodec/tmv.c

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00001 /*
00002  * 8088flex TMV video decoder
00003  * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
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 Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00029 #include "avcodec.h"
00030 
00031 #include "cga_data.h"
00032 
00033 typedef struct TMVContext {
00034     AVFrame pic;
00035 } TMVContext;
00036 
00037 static int tmv_decode_frame(AVCodecContext *avctx, void *data,
00038                             int *data_size, AVPacket *avpkt)
00039 {
00040     TMVContext *tmv    = avctx->priv_data;
00041     const uint8_t *src = avpkt->data;
00042     uint8_t *dst, *dst_char;
00043     unsigned char_cols = avctx->width >> 3;
00044     unsigned char_rows = avctx->height >> 3;
00045     unsigned x, y, mask, char_y, fg, bg, c;
00046 
00047     if (tmv->pic.data[0])
00048         avctx->release_buffer(avctx, &tmv->pic);
00049 
00050     if (avctx->get_buffer(avctx, &tmv->pic) < 0) {
00051         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00052         return -1;
00053     }
00054 
00055     if (avpkt->size < 2*char_rows*char_cols) {
00056         av_log(avctx, AV_LOG_ERROR,
00057                "Input buffer too small, truncated sample?\n");
00058         *data_size = 0;
00059         return -1;
00060     }
00061 
00062     tmv->pic.pict_type = FF_I_TYPE;
00063     tmv->pic.key_frame = 1;
00064     dst                = tmv->pic.data[0];
00065 
00066     tmv->pic.palette_has_changed = 1;
00067     memcpy(tmv->pic.data[1], ff_cga_palette, 16 * 4);
00068 
00069     for (y = 0; y < char_rows; y++) {
00070         for (x = 0; x < char_cols; x++) {
00071             c  = *src++ * 8;
00072             bg = *src  >> 4;
00073             fg = *src++ & 0xF;
00074 
00075             dst_char = dst + x * 8;
00076             for (char_y = 0; char_y < 8; char_y++) {
00077                 for (mask = 0x80; mask; mask >>= 1) {
00078                     *dst_char++ = ff_cga_font[c + char_y] & mask ? fg : bg;
00079                 }
00080                 dst_char += tmv->pic.linesize[0] - 8;
00081             }
00082         }
00083         dst += tmv->pic.linesize[0] * 8;
00084     }
00085 
00086     *data_size = sizeof(AVFrame);
00087     *(AVFrame *)data = tmv->pic;
00088     return avpkt->size;
00089 }
00090 
00091 static av_cold int tmv_decode_close(AVCodecContext *avctx)
00092 {
00093     TMVContext *tmv = avctx->priv_data;
00094 
00095     if (tmv->pic.data[0])
00096         avctx->release_buffer(avctx, &tmv->pic);
00097 
00098     return 0;
00099 }
00100 
00101 AVCodec tmv_decoder = {
00102     .name           = "tmv",
00103     .type           = AVMEDIA_TYPE_VIDEO,
00104     .id             = CODEC_ID_TMV,
00105     .priv_data_size = sizeof(TMVContext),
00106     .close          = tmv_decode_close,
00107     .decode         = tmv_decode_frame,
00108     .capabilities   = CODEC_CAP_DR1,
00109     .long_name      = NULL_IF_CONFIG_SMALL("8088flex TMV"),
00110 };

Generated on Fri Sep 16 2011 17:17:44 for FFmpeg by  doxygen 1.7.1