ffmpeg/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 "internal.h"
  24 #include "mjpeg.h"
  25 #include "mjpegdec.h"
  26 #include "libavutil/imgutils.h"
  27
  28 typedef struct {
  29     MJpegDecodeContext mjpeg_ctx;
  30     int is_mjpeg;
  31     int interlace; //FIXME use frame.interlaced_frame
  32     int tff;
  33 } AVRnContext;
  34
  35 static av_cold int init(AVCodecContext *avctx)
  36 {
  37     AVRnContext *a = avctx->priv_data;
  38     int ret;
  39
  40     // Support "Resolution 1:1" for Avid AVI Codec
  41     a->is_mjpeg = avctx->extradata_size < 31 || memcmp(&avctx->extradata[28], "1:1", 3);
  42
  43     if(!a->is_mjpeg && avctx->lowres) {
  44         av_log(avctx, AV_LOG_ERROR, "lowres is not possible with rawvideo\n");
  45         return AVERROR(EINVAL);
  46     }
  47
  48     if(a->is_mjpeg)
  49         return ff_mjpeg_decode_init(avctx);
  50
  51     if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
  52         return ret;
  53
  54     avctx->pix_fmt = AV_PIX_FMT_UYVY422;
  55
  56     if(avctx->extradata_size >= 9 && avctx->extradata[4]+28 < avctx->extradata_size) {
  57         int ndx = avctx->extradata[4] + 4;
  58         a->interlace = !memcmp(avctx->extradata + ndx, "1:1(", 4);
  59         if(a->interlace) {
  60             a->tff = avctx->extradata[ndx + 24] == 1;
  61         }
  62     }
  63
  64     return 0;
  65 }
  66
  67 static av_cold int end(AVCodecContext *avctx)
  68 {
  69     AVRnContext *a = avctx->priv_data;
  70
  71     if(a->is_mjpeg)
  72         ff_mjpeg_decode_end(avctx);
  73
  74     return 0;
  75 }
  76
  77 static int decode_frame(AVCodecContext *avctx, void *data,
  78                         int *got_frame, AVPacket *avpkt)
  79 {
  80     AVRnContext *a = avctx->priv_data;
  81     AVFrame *p = data;
  82     const uint8_t *buf = avpkt->data;
  83     int buf_size       = avpkt->size;
  84     int y, ret, true_height;
  85
  86     if(a->is_mjpeg)
  87         return ff_mjpeg_decode_frame(avctx, data, got_frame, avpkt);
  88
  89     true_height    = buf_size / (2*avctx->width);
  90
  91     if(buf_size < 2*avctx->width * avctx->height) {
  92         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
  93         return AVERROR_INVALIDDATA;
  94     }
  95
  96     if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
  97         return ret;
  98     p->pict_type= AV_PICTURE_TYPE_I;
  99     p->key_frame= 1;
 100
 101     if(a->interlace) {
 102         buf += (true_height - avctx->height)*avctx->width;
 103         for(y = 0; y < avctx->height-1; y+=2) {
 104             memcpy(p->data[0] + (y+ a->tff)*p->linesize[0], buf                             , 2*avctx->width);
 105             memcpy(p->data[0] + (y+!a->tff)*p->linesize[0], buf + avctx->width*true_height+4, 2*avctx->width);
 106             buf += 2*avctx->width;
 107         }
 108     } else {
 109         buf += (true_height - avctx->height)*avctx->width*2;
 110         for(y = 0; y < avctx->height; y++) {
 111             memcpy(p->data[0] + y*p->linesize[0], buf, 2*avctx->width);
 112             buf += 2*avctx->width;
 113         }
 114     }
 115
 116     *got_frame      = 1;
 117     return buf_size;
 118 }
 119
 120 AVCodec ff_avrn_decoder = {
 121     .name           = "avrn",
 122     .long_name      = NULL_IF_CONFIG_SMALL("Avid AVI Codec"),
 123     .type           = AVMEDIA_TYPE_VIDEO,
 124     .id             = AV_CODEC_ID_AVRN,
 125     .priv_data_size = sizeof(AVRnContext),
 126     .init           = init,
 127     .close          = end,
 128     .decode         = decode_frame,
 129     .capabilities   = CODEC_CAP_DR1,
 130     .max_lowres     = 3,
 131 };