libavcodec/avrndec.c

   1 /*
   2  * AVRn decoder
   3  * Copyright (c) 2012 Michael Niedermayer
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "avcodec.h"
  23 #include "codec_internal.h"
  24 #include "internal.h"
  25 #include "libavutil/imgutils.h"
  26
  27 typedef struct {
  28     int interlace;
  29     int tff;
  30 } AVRnContext;
  31
  32 static av_cold int init(AVCodecContext *avctx)
  33 {
  34     AVRnContext *a = avctx->priv_data;
  35     int ret;
  36
  37     if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
  38         return ret;
  39
  40     avctx->pix_fmt = AV_PIX_FMT_UYVY422;
  41
  42     if(avctx->extradata_size >= 9 && avctx->extradata[4]+28 < avctx->extradata_size) {
  43         int ndx = avctx->extradata[4] + 4;
  44         a->interlace = !memcmp(avctx->extradata + ndx, "1:1(", 4);
  45         if(a->interlace) {
  46             a->tff = avctx->extradata[ndx + 24] == 1;
  47         }
  48     }
  49
  50     return 0;
  51 }
  52
  53 static int decode_frame(AVCodecContext *avctx, AVFrame *p,
  54                         int *got_frame, AVPacket *avpkt)
  55 {
  56     AVRnContext *a = avctx->priv_data;
  57     const uint8_t *buf = avpkt->data;
  58     int buf_size       = avpkt->size;
  59     int y, ret, true_height;
  60
  61     true_height    = buf_size / (2*avctx->width);
  62
  63     if(buf_size < 2*avctx->width * avctx->height) {
  64         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
  65         return AVERROR_INVALIDDATA;
  66     }
  67
  68     if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
  69         return ret;
  70     p->pict_type= AV_PICTURE_TYPE_I;
  71     p->key_frame= 1;
  72
  73     if(a->interlace) {
  74         buf += (true_height - avctx->height)*avctx->width;
  75         for(y = 0; y < avctx->height-1; y+=2) {
  76             memcpy(p->data[0] + (y+ a->tff)*p->linesize[0], buf                             , 2*avctx->width);
  77             memcpy(p->data[0] + (y+!a->tff)*p->linesize[0], buf + avctx->width*true_height+4, 2*avctx->width);
  78             buf += 2*avctx->width;
  79         }
  80     } else {
  81         buf += (true_height - avctx->height)*avctx->width*2;
  82         for(y = 0; y < avctx->height; y++) {
  83             memcpy(p->data[0] + y*p->linesize[0], buf, 2*avctx->width);
  84             buf += 2*avctx->width;
  85         }
  86     }
  87
  88     *got_frame      = 1;
  89     return buf_size;
  90 }
  91
  92 const FFCodec ff_avrn_decoder = {
  93     .p.name         = "avrn",
  94     .p.long_name    = NULL_IF_CONFIG_SMALL("Avid AVI Codec"),
  95     .p.type         = AVMEDIA_TYPE_VIDEO,
  96     .p.id           = AV_CODEC_ID_AVRN,
  97     .priv_data_size = sizeof(AVRnContext),
  98     .init           = init,
  99     FF_CODEC_DECODE_CB(decode_frame),
 100     .p.capabilities = AV_CODEC_CAP_DR1,
 101     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
 102 };