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lavfutils.c
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1 /*
2  * Copyright 2012 Stefano Sabatini <stefasab gmail com>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "libavutil/imgutils.h"
22 #include "lavfutils.h"
23 
24 int ff_load_image(uint8_t *data[4], int linesize[4],
25  int *w, int *h, enum AVPixelFormat *pix_fmt,
26  const char *filename, void *log_ctx)
27 {
28  AVInputFormat *iformat = NULL;
29  AVFormatContext *format_ctx = NULL;
30  AVCodec *codec;
31  AVCodecContext *codec_ctx;
32  AVFrame *frame;
33  int frame_decoded, ret = 0;
34  AVPacket pkt;
35 
36  av_init_packet(&pkt);
37 
39 
40  iformat = av_find_input_format("image2");
41  if ((ret = avformat_open_input(&format_ctx, filename, iformat, NULL)) < 0) {
42  av_log(log_ctx, AV_LOG_ERROR,
43  "Failed to open input file '%s'\n", filename);
44  return ret;
45  }
46 
47  if ((ret = avformat_find_stream_info(format_ctx, NULL)) < 0) {
48  av_log(log_ctx, AV_LOG_ERROR, "Find stream info failed\n");
49  return ret;
50  }
51 
52  codec_ctx = format_ctx->streams[0]->codec;
53  codec = avcodec_find_decoder(codec_ctx->codec_id);
54  if (!codec) {
55  av_log(log_ctx, AV_LOG_ERROR, "Failed to find codec\n");
56  ret = AVERROR(EINVAL);
57  goto end;
58  }
59 
60  if ((ret = avcodec_open2(codec_ctx, codec, NULL)) < 0) {
61  av_log(log_ctx, AV_LOG_ERROR, "Failed to open codec\n");
62  goto end;
63  }
64 
65  if (!(frame = av_frame_alloc()) ) {
66  av_log(log_ctx, AV_LOG_ERROR, "Failed to alloc frame\n");
67  ret = AVERROR(ENOMEM);
68  goto end;
69  }
70 
71  ret = av_read_frame(format_ctx, &pkt);
72  if (ret < 0) {
73  av_log(log_ctx, AV_LOG_ERROR, "Failed to read frame from file\n");
74  goto end;
75  }
76 
77  ret = avcodec_decode_video2(codec_ctx, frame, &frame_decoded, &pkt);
78  if (ret < 0 || !frame_decoded) {
79  av_log(log_ctx, AV_LOG_ERROR, "Failed to decode image from file\n");
80  if (ret >= 0)
81  ret = -1;
82  goto end;
83  }
84 
85  *w = frame->width;
86  *h = frame->height;
87  *pix_fmt = frame->format;
88 
89  if ((ret = av_image_alloc(data, linesize, *w, *h, *pix_fmt, 16)) < 0)
90  goto end;
91  ret = 0;
92 
93  av_image_copy(data, linesize, (const uint8_t **)frame->data, frame->linesize, *pix_fmt, *w, *h);
94 
95 end:
96  av_free_packet(&pkt);
97  avcodec_close(codec_ctx);
98  avformat_close_input(&format_ctx);
99  av_freep(&frame);
100 
101  if (ret < 0)
102  av_log(log_ctx, AV_LOG_ERROR, "Error loading image file '%s'\n", filename);
103  return ret;
104 }