lavc: add a wrapper for AVCodecContext.get_buffer().
[libav.git] / libavcodec / frwu.c
1 /*
2 * Forward Uncompressed
3 *
4 * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
5 *
6 * This file is part of Libav.
7 *
8 * Libav 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 * Libav 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 Libav; 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 "bytestream.h"
25 #include "internal.h"
26
27 static av_cold int decode_init(AVCodecContext *avctx)
28 {
29 if (avctx->width & 1) {
30 av_log(avctx, AV_LOG_ERROR, "frwu needs even width\n");
31 return AVERROR(EINVAL);
32 }
33 avctx->pix_fmt = AV_PIX_FMT_UYVY422;
34
35 avctx->coded_frame = avcodec_alloc_frame();
36 if (!avctx->coded_frame)
37 return AVERROR(ENOMEM);
38
39 return 0;
40 }
41
42 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
43 AVPacket *avpkt)
44 {
45 int field, ret;
46 AVFrame *pic = avctx->coded_frame;
47 const uint8_t *buf = avpkt->data;
48 const uint8_t *buf_end = buf + avpkt->size;
49
50 if (pic->data[0])
51 avctx->release_buffer(avctx, pic);
52
53 if (avpkt->size < avctx->width * 2 * avctx->height + 4 + 2*8) {
54 av_log(avctx, AV_LOG_ERROR, "Packet is too small.\n");
55 return AVERROR_INVALIDDATA;
56 }
57 if (bytestream_get_le32(&buf) != MKTAG('F', 'R', 'W', '1')) {
58 av_log(avctx, AV_LOG_ERROR, "incorrect marker\n");
59 return AVERROR_INVALIDDATA;
60 }
61
62 pic->reference = 0;
63 if ((ret = ff_get_buffer(avctx, pic)) < 0) {
64 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
65 return ret;
66 }
67
68 pic->pict_type = AV_PICTURE_TYPE_I;
69 pic->key_frame = 1;
70 pic->interlaced_frame = 1;
71 pic->top_field_first = 1;
72
73 for (field = 0; field < 2; field++) {
74 int i;
75 int field_h = (avctx->height + !field) >> 1;
76 int field_size, min_field_size = avctx->width * 2 * field_h;
77 uint8_t *dst = pic->data[0];
78 if (buf_end - buf < 8)
79 return AVERROR_INVALIDDATA;
80 buf += 4; // flags? 0x80 == bottom field maybe?
81 field_size = bytestream_get_le32(&buf);
82 if (field_size < min_field_size) {
83 av_log(avctx, AV_LOG_ERROR, "Field size %i is too small (required %i)\n", field_size, min_field_size);
84 return AVERROR_INVALIDDATA;
85 }
86 if (buf_end - buf < field_size) {
87 av_log(avctx, AV_LOG_ERROR, "Packet is too small, need %i, have %i\n", field_size, (int)(buf_end - buf));
88 return AVERROR_INVALIDDATA;
89 }
90 if (field)
91 dst += pic->linesize[0];
92 for (i = 0; i < field_h; i++) {
93 memcpy(dst, buf, avctx->width * 2);
94 buf += avctx->width * 2;
95 dst += pic->linesize[0] << 1;
96 }
97 buf += field_size - min_field_size;
98 }
99
100 *data_size = sizeof(AVFrame);
101 *(AVFrame*)data = *pic;
102
103 return avpkt->size;
104 }
105
106 static av_cold int decode_close(AVCodecContext *avctx)
107 {
108 AVFrame *pic = avctx->coded_frame;
109 if (pic->data[0])
110 avctx->release_buffer(avctx, pic);
111 av_freep(&avctx->coded_frame);
112
113 return 0;
114 }
115
116 AVCodec ff_frwu_decoder = {
117 .name = "frwu",
118 .type = AVMEDIA_TYPE_VIDEO,
119 .id = AV_CODEC_ID_FRWU,
120 .init = decode_init,
121 .close = decode_close,
122 .decode = decode_frame,
123 .capabilities = CODEC_CAP_DR1,
124 .long_name = NULL_IF_CONFIG_SMALL("Forward Uncompressed"),
125 };