libavcodec/frwu.c

   1 /*
   2  * Forward Uncompressed
   3  *
   4  * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "avcodec.h"
  24 #include "bytestream.h"
  25 #include "libavutil/intreadwrite.h"
  26
  27 static av_cold int decode_init(AVCodecContext *avctx)
  28 {
  29     if (avctx->width & 1) {
  30         av_log(avctx, AV_LOG_ERROR, "FRWU needs even width\n");
  31         return -1;
  32     }
  33     avctx->pix_fmt = PIX_FMT_UYVY422;
  34
  35     avctx->coded_frame = avcodec_alloc_frame();
  36
  37     return 0;
  38 }
  39
  40 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
  41                         AVPacket *avpkt)
  42 {
  43     int field;
  44     AVFrame *pic = avctx->coded_frame;
  45     const uint8_t *buf = avpkt->data;
  46     const uint8_t *buf_end = buf + avpkt->size;
  47
  48     if (pic->data[0])
  49         avctx->release_buffer(avctx, pic);
  50
  51     if (avpkt->size < avctx->width * 2 * avctx->height + 4 + 2*8) {
  52         av_log(avctx, AV_LOG_ERROR, "Packet is too small.\n");
  53         return -1;
  54     }
  55     if (bytestream_get_le32(&buf) != AV_RL32("FRW1")) {
  56         av_log(avctx, AV_LOG_ERROR, "incorrect marker\n");
  57         return -1;
  58     }
  59
  60     pic->reference = 0;
  61     if (avctx->get_buffer(avctx, pic) < 0)
  62         return -1;
  63
  64     pic->pict_type = FF_I_TYPE;
  65     pic->key_frame = 1;
  66     pic->interlaced_frame = 1;
  67     pic->top_field_first = 1;
  68
  69     for (field = 0; field < 2; field++) {
  70         int i;
  71         int field_h = (avctx->height + !field) >> 1;
  72         int field_size, min_field_size = avctx->width * 2 * field_h;
  73         uint8_t *dst = pic->data[0];
  74         if (buf_end - buf < 8)
  75             return -1;
  76         buf += 4; // flags? 0x80 == bottom field maybe?
  77         field_size = bytestream_get_le32(&buf);
  78         if (field_size < min_field_size) {
  79             av_log(avctx, AV_LOG_ERROR, "Field size %i is too small (required %i)\n", field_size, min_field_size);
  80             return -1;
  81         }
  82         if (buf_end - buf < field_size) {
  83             av_log(avctx, AV_LOG_ERROR, "Packet is too small, need %i, have %i\n", field_size, (int)(buf_end - buf));
  84             return -1;
  85         }
  86         if (field)
  87             dst += pic->linesize[0];
  88         for (i = 0; i < field_h; i++) {
  89             memcpy(dst, buf, avctx->width * 2);
  90             buf += avctx->width * 2;
  91             dst += pic->linesize[0] << 1;
  92         }
  93         buf += field_size - min_field_size;
  94     }
  95
  96     *data_size = sizeof(AVFrame);
  97     *(AVFrame*)data = *pic;
  98
  99     return avpkt->size;
 100 }
 101
 102 static av_cold int decode_close(AVCodecContext *avctx)
 103 {
 104     AVFrame *pic = avctx->coded_frame;
 105     if (pic->data[0])
 106         avctx->release_buffer(avctx, pic);
 107     av_freep(&avctx->coded_frame);
 108
 109     return 0;
 110 }
 111
 112 AVCodec frwu_decoder = {
 113     "FRWU",
 114     CODEC_TYPE_VIDEO,
 115     CODEC_ID_FRWU,
 116     0,
 117     decode_init,
 118     NULL,
 119     decode_close,
 120     decode_frame,
 121     CODEC_CAP_DR1,
 122     .long_name = NULL_IF_CONFIG_SMALL("Forward Uncompressed"),
 123 };