ffmpeg/libavcodec/y41pdec.c

   1 /*
   2  * y41p decoder
   3  *
   4  * Copyright (c) 2012 Paul B Mahol
   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 "internal.h"
  25
  26 static av_cold int y41p_decode_init(AVCodecContext *avctx)
  27 {
  28     avctx->pix_fmt             = AV_PIX_FMT_YUV411P;
  29     avctx->bits_per_raw_sample = 12;
  30
  31     if (avctx->width & 7) {
  32         av_log(avctx, AV_LOG_WARNING, "y41p requires width to be divisible by 8.\n");
  33     }
  34
  35     return 0;
  36 }
  37
  38 static int y41p_decode_frame(AVCodecContext *avctx, void *data,
  39                              int *got_frame, AVPacket *avpkt)
  40 {
  41     AVFrame *pic = data;
  42     uint8_t *src = avpkt->data;
  43     uint8_t *y, *u, *v;
  44     int i, j, ret;
  45
  46     if (avpkt->size < 1.5 * avctx->height * avctx->width) {
  47         av_log(avctx, AV_LOG_ERROR, "Insufficient input data.\n");
  48         return AVERROR(EINVAL);
  49     }
  50
  51     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
  52         return ret;
  53
  54     pic->key_frame = 1;
  55     pic->pict_type = AV_PICTURE_TYPE_I;
  56
  57     for (i = avctx->height - 1; i >= 0 ; i--) {
  58         y = &pic->data[0][i * pic->linesize[0]];
  59         u = &pic->data[1][i * pic->linesize[1]];
  60         v = &pic->data[2][i * pic->linesize[2]];
  61         for (j = 0; j < avctx->width; j += 8) {
  62             *(u++) = *src++;
  63             *(y++) = *src++;
  64             *(v++) = *src++;
  65             *(y++) = *src++;
  66
  67             *(u++) = *src++;
  68             *(y++) = *src++;
  69             *(v++) = *src++;
  70             *(y++) = *src++;
  71
  72             *(y++) = *src++;
  73             *(y++) = *src++;
  74             *(y++) = *src++;
  75             *(y++) = *src++;
  76         }
  77     }
  78
  79     *got_frame = 1;
  80
  81     return avpkt->size;
  82 }
  83
  84 AVCodec ff_y41p_decoder = {
  85     .name         = "y41p",
  86     .long_name    = NULL_IF_CONFIG_SMALL("Uncompressed YUV 4:1:1 12-bit"),
  87     .type         = AVMEDIA_TYPE_VIDEO,
  88     .id           = AV_CODEC_ID_Y41P,
  89     .init         = y41p_decode_init,
  90     .decode       = y41p_decode_frame,
  91     .capabilities = CODEC_CAP_DR1,
  92 };