blob: 087b18fb91f5663d7d7ce870aeb01b95470a63d9
1 | /* |
2 | * Alias PIX image decoder |
3 | * Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com> |
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 "libavutil/intreadwrite.h" |
23 | |
24 | #include "avcodec.h" |
25 | #include "bytestream.h" |
26 | #include "internal.h" |
27 | |
28 | #define ALIAS_HEADER_SIZE 10 |
29 | |
30 | static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, |
31 | AVPacket *avpkt) |
32 | { |
33 | AVFrame *f = data; |
34 | GetByteContext gb; |
35 | int width, height, ret, bits_pixel, pixel; |
36 | uint8_t *out_buf; |
37 | uint8_t count; |
38 | int x, y; |
39 | |
40 | bytestream2_init(&gb, avpkt->data, avpkt->size); |
41 | |
42 | if (bytestream2_get_bytes_left(&gb) < ALIAS_HEADER_SIZE) { |
43 | av_log(avctx, AV_LOG_ERROR, "Header too small %d.\n", avpkt->size); |
44 | return AVERROR_INVALIDDATA; |
45 | } |
46 | |
47 | width = bytestream2_get_be16u(&gb); |
48 | height = bytestream2_get_be16u(&gb); |
49 | bytestream2_skipu(&gb, 4); // obsolete X, Y offset |
50 | bits_pixel = bytestream2_get_be16u(&gb); |
51 | |
52 | if (bits_pixel == 24) |
53 | avctx->pix_fmt = AV_PIX_FMT_BGR24; |
54 | else if (bits_pixel == 8) |
55 | avctx->pix_fmt = AV_PIX_FMT_GRAY8; |
56 | else { |
57 | av_log(avctx, AV_LOG_ERROR, "Invalid pixel format.\n"); |
58 | return AVERROR_INVALIDDATA; |
59 | } |
60 | |
61 | ret = ff_set_dimensions(avctx, width, height); |
62 | if (ret < 0) |
63 | return ret; |
64 | |
65 | ret = ff_get_buffer(avctx, f, 0); |
66 | if (ret < 0) |
67 | return ret; |
68 | |
69 | f->pict_type = AV_PICTURE_TYPE_I; |
70 | f->key_frame = 1; |
71 | |
72 | x = 0; |
73 | y = 1; |
74 | out_buf = f->data[0]; |
75 | while (bytestream2_get_bytes_left(&gb) > 0) { |
76 | int i; |
77 | |
78 | /* set buffer at the right position at every new line */ |
79 | if (x == avctx->width) { |
80 | x = 0; |
81 | out_buf = f->data[0] + f->linesize[0] * y++; |
82 | if (y > avctx->height) { |
83 | av_log(avctx, AV_LOG_ERROR, |
84 | "Ended frame decoding with %d bytes left.\n", |
85 | bytestream2_get_bytes_left(&gb)); |
86 | return AVERROR_INVALIDDATA; |
87 | } |
88 | } |
89 | |
90 | /* read packet and copy data */ |
91 | count = bytestream2_get_byteu(&gb); |
92 | if (!count || x + count > avctx->width) { |
93 | av_log(avctx, AV_LOG_ERROR, "Invalid run length %d.\n", count); |
94 | return AVERROR_INVALIDDATA; |
95 | } |
96 | |
97 | if (avctx->pix_fmt == AV_PIX_FMT_BGR24) { |
98 | pixel = bytestream2_get_be24(&gb); |
99 | for (i = 0; i < count; i++) { |
100 | AV_WB24(out_buf, pixel); |
101 | out_buf += 3; |
102 | } |
103 | } else { // AV_PIX_FMT_GRAY8 |
104 | pixel = bytestream2_get_byte(&gb); |
105 | for (i = 0; i < count; i++) |
106 | *out_buf++ = pixel; |
107 | } |
108 | |
109 | x += i; |
110 | } |
111 | |
112 | if (x != width || y != height) { |
113 | av_log(avctx, AV_LOG_ERROR, "Picture stopped at %d,%d.\n", x, y); |
114 | return AVERROR_INVALIDDATA; |
115 | } |
116 | |
117 | *got_frame = 1; |
118 | return avpkt->size; |
119 | } |
120 | |
121 | AVCodec ff_alias_pix_decoder = { |
122 | .name = "alias_pix", |
123 | .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"), |
124 | .type = AVMEDIA_TYPE_VIDEO, |
125 | .id = AV_CODEC_ID_ALIAS_PIX, |
126 | .decode = decode_frame, |
127 | .capabilities = AV_CODEC_CAP_DR1, |
128 | }; |
129 |