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libavcodec/dxtory.c

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00001 /*
00002  * Dxtory decoder
00003  *
00004  * Copyright (c) 2011 Konstantin Shishkov
00005  *
00006  * This file is part of Libav.
00007  *
00008  * Libav is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * Libav is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with Libav; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "avcodec.h"
00024 #include "libavutil/intreadwrite.h"
00025 
00026 static av_cold int decode_init(AVCodecContext *avctx)
00027 {
00028     avctx->pix_fmt     = PIX_FMT_YUV420P;
00029     avctx->coded_frame = avcodec_alloc_frame();
00030     if (!avctx->coded_frame)
00031         return AVERROR(ENOMEM);
00032 
00033     return 0;
00034 }
00035 
00036 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
00037                         AVPacket *avpkt)
00038 {
00039     int h, w;
00040     AVFrame *pic = avctx->coded_frame;
00041     const uint8_t *src = avpkt->data;
00042     uint8_t *Y1, *Y2, *U, *V;
00043     int ret;
00044 
00045     if (pic->data[0])
00046         avctx->release_buffer(avctx, pic);
00047 
00048     if (avpkt->size < avctx->width * avctx->height * 3 / 2 + 16) {
00049         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
00050         return AVERROR_INVALIDDATA;
00051     }
00052 
00053     pic->reference = 0;
00054     if ((ret = avctx->get_buffer(avctx, pic)) < 0)
00055         return ret;
00056 
00057     pic->pict_type = AV_PICTURE_TYPE_I;
00058     pic->key_frame = 1;
00059 
00060     if (AV_RL32(src) != 0x01000002) {
00061         av_log_ask_for_sample(avctx, "Unknown frame header %X\n", AV_RL32(src));
00062         return AVERROR_PATCHWELCOME;
00063     }
00064     src += 16;
00065 
00066     Y1 = pic->data[0];
00067     Y2 = pic->data[0] + pic->linesize[0];
00068     U  = pic->data[1];
00069     V  = pic->data[2];
00070     for (h = 0; h < avctx->height; h += 2) {
00071         for (w = 0; w < avctx->width; w += 2) {
00072             AV_WN16A(Y1 + w, AV_RN16A(src));
00073             AV_WN16A(Y2 + w, AV_RN16A(src + 2));
00074             U[w >> 1] = src[4] + 0x80;
00075             V[w >> 1] = src[5] + 0x80;
00076             src += 6;
00077         }
00078         Y1 += pic->linesize[0] << 1;
00079         Y2 += pic->linesize[0] << 1;
00080         U  += pic->linesize[1];
00081         V  += pic->linesize[2];
00082     }
00083 
00084     *data_size      = sizeof(AVFrame);
00085     *(AVFrame*)data = *pic;
00086 
00087     return avpkt->size;
00088 }
00089 
00090 static av_cold int decode_close(AVCodecContext *avctx)
00091 {
00092     AVFrame *pic = avctx->coded_frame;
00093     if (pic->data[0])
00094         avctx->release_buffer(avctx, pic);
00095     av_freep(&avctx->coded_frame);
00096 
00097     return 0;
00098 }
00099 
00100 AVCodec ff_dxtory_decoder = {
00101     .name           = "dxtory",
00102     .long_name      = NULL_IF_CONFIG_SMALL("Dxtory"),
00103     .type           = AVMEDIA_TYPE_VIDEO,
00104     .id             = CODEC_ID_DXTORY,
00105     .init           = decode_init,
00106     .close          = decode_close,
00107     .decode         = decode_frame,
00108     .capabilities   = CODEC_CAP_DR1,
00109 };
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