ffmpeg/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 "internal.h"
  26 #include "libavutil/opt.h"
  27
  28 typedef struct {
  29     AVClass *av_class;
  30     int change_field_order;
  31 } FRWUContext;
  32
  33 static av_cold int decode_init(AVCodecContext *avctx)
  34 {
  35     if (avctx->width & 1) {
  36         av_log(avctx, AV_LOG_ERROR, "frwu needs even width\n");
  37         return AVERROR(EINVAL);
  38     }
  39     avctx->pix_fmt = AV_PIX_FMT_UYVY422;
  40
  41     return 0;
  42 }
  43
  44 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
  45                         AVPacket *avpkt)
  46 {
  47     FRWUContext *s = avctx->priv_data;
  48     int field, ret;
  49     AVFrame *pic = data;
  50     const uint8_t *buf = avpkt->data;
  51     const uint8_t *buf_end = buf + avpkt->size;
  52
  53     if (avpkt->size < avctx->width * 2 * avctx->height + 4 + 2*8) {
  54         av_log(avctx, AV_LOG_ERROR, "Packet is too small.\n");
  55         return AVERROR_INVALIDDATA;
  56     }
  57     if (bytestream_get_le32(&buf) != MKTAG('F', 'R', 'W', '1')) {
  58         av_log(avctx, AV_LOG_ERROR, "incorrect marker\n");
  59         return AVERROR_INVALIDDATA;
  60     }
  61
  62     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
  63         return ret;
  64
  65     pic->pict_type = AV_PICTURE_TYPE_I;
  66     pic->key_frame = 1;
  67
  68     for (field = 0; field < 2; field++) {
  69         int i;
  70         int field_h = (avctx->height + !field) >> 1;
  71         int field_size, min_field_size = avctx->width * 2 * field_h;
  72         uint8_t *dst = pic->data[0];
  73         if (buf_end - buf < 8)
  74             return AVERROR_INVALIDDATA;
  75         buf += 4; // flags? 0x80 == bottom field maybe?
  76         field_size = bytestream_get_le32(&buf);
  77         if (field_size < min_field_size) {
  78             av_log(avctx, AV_LOG_ERROR, "Field size %i is too small (required %i)\n", field_size, min_field_size);
  79             return AVERROR_INVALIDDATA;
  80         }
  81         if (buf_end - buf < field_size) {
  82             av_log(avctx, AV_LOG_ERROR, "Packet is too small, need %i, have %i\n", field_size, (int)(buf_end - buf));
  83             return AVERROR_INVALIDDATA;
  84         }
  85         if (field ^ s->change_field_order) {
  86             dst += pic->linesize[0];
  87         } else if (s->change_field_order) {
  88             dst += 2 * pic->linesize[0];
  89         }
  90         for (i = 0; i < field_h; i++) {
  91             if (s->change_field_order && field && i == field_h - 1)
  92                 dst = pic->data[0];
  93             memcpy(dst, buf, avctx->width * 2);
  94             buf += avctx->width * 2;
  95             dst += pic->linesize[0] << 1;
  96         }
  97         buf += field_size - min_field_size;
  98     }
  99
 100     *got_frame = 1;
 101
 102     return avpkt->size;
 103 }
 104
 105 static const AVOption frwu_options[] = {
 106     {"change_field_order", "Change field order", offsetof(FRWUContext, change_field_order), FF_OPT_TYPE_INT,
 107      {.i64 = 0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_VIDEO_PARAM},
 108     {NULL}
 109 };
 110
 111 static const AVClass frwu_class = {
 112     .class_name = "frwu Decoder",
 113     .item_name  = av_default_item_name,
 114     .option     = frwu_options,
 115     .version    = LIBAVUTIL_VERSION_INT,
 116 };
 117
 118 AVCodec ff_frwu_decoder = {
 119     .name           = "frwu",
 120     .long_name      = NULL_IF_CONFIG_SMALL("Forward Uncompressed"),
 121     .type           = AVMEDIA_TYPE_VIDEO,
 122     .id             = AV_CODEC_ID_FRWU,
 123     .priv_data_size = sizeof(FRWUContext),
 124     .init           = decode_init,
 125     .decode         = decode_frame,
 126     .capabilities   = CODEC_CAP_DR1,
 127     .priv_class     = &frwu_class,
 128 };