FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
avrndec.c
Go to the documentation of this file.
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 {
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;
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 
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 };