1 /*
2 * PGX image format
3 * Copyright (c) 2020 Gautam Ramakrishnan
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 "bytestream.h"
25 #include "codec_internal.h"
26 #include "libavutil/imgutils.h"
27
pgx_get_number(AVCodecContext * avctx,GetByteContext * g,int * number)28 static int pgx_get_number(AVCodecContext *avctx, GetByteContext *g, int *number) {
29 int ret = AVERROR_INVALIDDATA;
30 char digit;
31
32 *number = 0;
33 while (1) {
34 uint64_t temp;
35 if (bytestream2_get_bytes_left(g) <= 0)
36 return AVERROR_INVALIDDATA;
37 digit = bytestream2_get_byteu(g);
38 if (digit == ' ' || digit == 0xA || digit == 0xD)
39 break;
40 else if (digit < '0' || digit > '9')
41 return AVERROR_INVALIDDATA;
42
43 temp = (uint64_t)10 * (*number) + (digit - '0');
44 if (temp > INT_MAX)
45 return AVERROR_INVALIDDATA;
46 *number = temp;
47 ret = 0;
48 }
49
50 return ret;
51 }
52
pgx_decode_header(AVCodecContext * avctx,GetByteContext * g,int * depth,int * width,int * height,int * sign)53 static int pgx_decode_header(AVCodecContext *avctx, GetByteContext *g,
54 int *depth, int *width, int *height,
55 int *sign)
56 {
57 int byte;
58
59 if (bytestream2_get_bytes_left(g) < 12)
60 return AVERROR_INVALIDDATA;
61
62 bytestream2_skipu(g, 6);
63
64 // Is the component signed?
65 byte = bytestream2_peek_byteu(g);
66 if (byte == '+') {
67 *sign = 0;
68 bytestream2_skipu(g, 1);
69 } else if (byte == '-') {
70 *sign = 1;
71 bytestream2_skipu(g, 1);
72 }
73
74 byte = bytestream2_peek_byteu(g);
75 if (byte == ' ')
76 bytestream2_skipu(g, 1);
77
78 if (pgx_get_number(avctx, g, depth))
79 goto error;
80 if (pgx_get_number(avctx, g, width))
81 goto error;
82 if (pgx_get_number(avctx, g, height))
83 goto error;
84
85 if (bytestream2_peek_byte(g) == 0xA)
86 bytestream2_skip(g, 1);
87 return 0;
88
89 error:
90 av_log(avctx, AV_LOG_ERROR, "Error in decoding header.\n");
91 return AVERROR_INVALIDDATA;
92 }
93
94 #define WRITE_FRAME(D, PIXEL, suffix) \
95 static inline void write_frame_ ##D(AVFrame *frame, GetByteContext *g, \
96 int width, int height, int sign, int depth) \
97 { \
98 const unsigned offset = sign ? (1 << (D - 1)) : 0; \
99 int i, j; \
100 for (i = 0; i < height; i++) { \
101 PIXEL *line = (PIXEL*)(frame->data[0] + i * frame->linesize[0]); \
102 for (j = 0; j < width; j++) { \
103 unsigned val = bytestream2_get_ ##suffix##u(g) << (D - depth); \
104 val ^= offset; \
105 *(line + j) = val; \
106 } \
107 } \
108 } \
109
110 WRITE_FRAME(8, uint8_t, byte)
111 WRITE_FRAME(16, uint16_t, be16)
112
pgx_decode_frame(AVCodecContext * avctx,AVFrame * p,int * got_frame,AVPacket * avpkt)113 static int pgx_decode_frame(AVCodecContext *avctx, AVFrame *p,
114 int *got_frame, AVPacket *avpkt)
115 {
116 int ret;
117 int bpp;
118 int width, height, depth;
119 int sign = 0;
120 GetByteContext g;
121 bytestream2_init(&g, avpkt->data, avpkt->size);
122
123 if ((ret = pgx_decode_header(avctx, &g, &depth, &width, &height, &sign)) < 0)
124 return ret;
125
126 if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
127 return ret;
128
129 if (depth > 0 && depth <= 8) {
130 avctx->pix_fmt = AV_PIX_FMT_GRAY8;
131 bpp = 8;
132 } else if (depth > 0 && depth <= 16) {
133 avctx->pix_fmt = AV_PIX_FMT_GRAY16;
134 bpp = 16;
135 } else {
136 av_log(avctx, AV_LOG_ERROR, "depth %d is invalid or unsupported.\n", depth);
137 return AVERROR_PATCHWELCOME;
138 }
139 if (bytestream2_get_bytes_left(&g) < width * height * (bpp >> 3))
140 return AVERROR_INVALIDDATA;
141 if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
142 return ret;
143 p->pict_type = AV_PICTURE_TYPE_I;
144 p->key_frame = 1;
145 avctx->bits_per_raw_sample = depth;
146 if (bpp == 8)
147 write_frame_8(p, &g, width, height, sign, depth);
148 else if (bpp == 16)
149 write_frame_16(p, &g, width, height, sign, depth);
150 *got_frame = 1;
151 return 0;
152 }
153
154 const FFCodec ff_pgx_decoder = {
155 .p.name = "pgx",
156 .p.long_name = NULL_IF_CONFIG_SMALL("PGX (JPEG2000 Test Format)"),
157 .p.type = AVMEDIA_TYPE_VIDEO,
158 .p.id = AV_CODEC_ID_PGX,
159 .p.capabilities = AV_CODEC_CAP_DR1,
160 FF_CODEC_DECODE_CB(pgx_decode_frame),
161 };
162