blob: 07cdd503687a554fdda541ee30a7ca5116cf3cc8
1 | /* |
2 | * CPiA video decoder. |
3 | * Copyright (c) 2010 Hans de Goede <hdegoede@redhat.com> |
4 | * |
5 | * This decoder is based on the LGPL code available at |
6 | * https://v4l4j.googlecode.com/svn/v4l4j/trunk/libvideo/libv4lconvert/cpia1.c |
7 | * |
8 | * This file is part of FFmpeg. |
9 | * |
10 | * FFmpeg is free software; you can redistribute it and/or |
11 | * modify it under the terms of the GNU Lesser General Public |
12 | * License as published by the Free Software Foundation; either |
13 | * version 2.1 of the License, or (at your option) any later version. |
14 | * |
15 | * FFmpeg is distributed in the hope that it will be useful, |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
18 | * Lesser General Public License for more details. |
19 | * |
20 | * You should have received a copy of the GNU Lesser General Public |
21 | * License along with FFmpeg; if not, write to the Free Software |
22 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
23 | */ |
24 | |
25 | #include "avcodec.h" |
26 | #include "get_bits.h" |
27 | #include "internal.h" |
28 | |
29 | |
30 | #define FRAME_HEADER_SIZE 64 |
31 | #define MAGIC_0 0x19 /**< First header byte */ |
32 | #define MAGIC_1 0x68 /**< Second header byte */ |
33 | #define SUBSAMPLE_420 0 |
34 | #define SUBSAMPLE_422 1 |
35 | #define YUVORDER_YUYV 0 |
36 | #define YUVORDER_UYVY 1 |
37 | #define NOT_COMPRESSED 0 |
38 | #define COMPRESSED 1 |
39 | #define NO_DECIMATION 0 |
40 | #define DECIMATION_ENAB 1 |
41 | #define EOL 0xfd /**< End Of Line marker */ |
42 | #define EOI 0xff /**< End Of Image marker */ |
43 | |
44 | |
45 | typedef struct { |
46 | AVFrame *frame; |
47 | } CpiaContext; |
48 | |
49 | |
50 | static int cpia_decode_frame(AVCodecContext *avctx, |
51 | void *data, int *got_frame, AVPacket* avpkt) |
52 | { |
53 | CpiaContext* const cpia = avctx->priv_data; |
54 | int i,j,ret; |
55 | |
56 | uint8_t* const header = avpkt->data; |
57 | uint8_t* src; |
58 | int src_size; |
59 | uint16_t linelength; |
60 | uint8_t skip; |
61 | |
62 | AVFrame *frame = cpia->frame; |
63 | uint8_t *y, *u, *v, *y_end, *u_end, *v_end; |
64 | |
65 | // Check header |
66 | if ( avpkt->size < FRAME_HEADER_SIZE |
67 | || header[0] != MAGIC_0 || header[1] != MAGIC_1 |
68 | || (header[17] != SUBSAMPLE_420 && header[17] != SUBSAMPLE_422) |
69 | || (header[18] != YUVORDER_YUYV && header[18] != YUVORDER_UYVY) |
70 | || (header[28] != NOT_COMPRESSED && header[28] != COMPRESSED) |
71 | || (header[29] != NO_DECIMATION && header[29] != DECIMATION_ENAB) |
72 | ) { |
73 | av_log(avctx, AV_LOG_ERROR, "Invalid header!\n"); |
74 | return AVERROR_INVALIDDATA; |
75 | } |
76 | |
77 | // currently unsupported properties |
78 | if (header[17] == SUBSAMPLE_422) { |
79 | avpriv_report_missing_feature(avctx, "4:2:2 subsampling"); |
80 | return AVERROR_PATCHWELCOME; |
81 | } |
82 | if (header[18] == YUVORDER_UYVY) { |
83 | avpriv_report_missing_feature(avctx, "YUV byte order UYVY"); |
84 | return AVERROR_PATCHWELCOME; |
85 | } |
86 | if (header[29] == DECIMATION_ENAB) { |
87 | avpriv_report_missing_feature(avctx, "Decimation"); |
88 | return AVERROR_PATCHWELCOME; |
89 | } |
90 | |
91 | src = header + FRAME_HEADER_SIZE; |
92 | src_size = avpkt->size - FRAME_HEADER_SIZE; |
93 | |
94 | if (header[28] == NOT_COMPRESSED) { |
95 | frame->pict_type = AV_PICTURE_TYPE_I; |
96 | frame->key_frame = 1; |
97 | } else { |
98 | frame->pict_type = AV_PICTURE_TYPE_P; |
99 | frame->key_frame = 0; |
100 | } |
101 | |
102 | // Get buffer filled with previous frame |
103 | if ((ret = ff_reget_buffer(avctx, frame)) < 0) |
104 | return ret; |
105 | |
106 | |
107 | for ( i = 0; |
108 | i < frame->height; |
109 | i++, src += linelength, src_size -= linelength |
110 | ) { |
111 | // Read line length, two byte little endian |
112 | linelength = AV_RL16(src); |
113 | src += 2; |
114 | |
115 | if (src_size < linelength) { |
116 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); |
117 | av_log(avctx, AV_LOG_WARNING, "Frame ended unexpectedly!\n"); |
118 | break; |
119 | } |
120 | if (src[linelength - 1] != EOL) { |
121 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); |
122 | av_log(avctx, AV_LOG_WARNING, "Wrong line length %d or line not terminated properly (found 0x%02x)!\n", linelength, src[linelength - 1]); |
123 | break; |
124 | } |
125 | |
126 | /* Update the data pointers. Y data is on every line. |
127 | * U and V data on every second line |
128 | */ |
129 | y = &frame->data[0][i * frame->linesize[0]]; |
130 | u = &frame->data[1][(i >> 1) * frame->linesize[1]]; |
131 | v = &frame->data[2][(i >> 1) * frame->linesize[2]]; |
132 | y_end = y + frame->linesize[0] - 1; |
133 | u_end = u + frame->linesize[1] - 1; |
134 | v_end = v + frame->linesize[2] - 1; |
135 | |
136 | if ((i & 1) && header[17] == SUBSAMPLE_420) { |
137 | /* We are on an odd line and 420 subsample is used. |
138 | * On this line only Y values are specified, one per pixel. |
139 | */ |
140 | for (j = 0; j < linelength - 1; j++) { |
141 | if (y > y_end) { |
142 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); |
143 | av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n"); |
144 | break; |
145 | } |
146 | if ((src[j] & 1) && header[28] == COMPRESSED) { |
147 | /* It seems that odd lines are always uncompressed, but |
148 | * we do it according to specification anyways. |
149 | */ |
150 | skip = src[j] >> 1; |
151 | y += skip; |
152 | } else { |
153 | *(y++) = src[j]; |
154 | } |
155 | } |
156 | } else if (header[17] == SUBSAMPLE_420) { |
157 | /* We are on an even line and 420 subsample is used. |
158 | * On this line each pair of pixels is described by four bytes. |
159 | */ |
160 | for (j = 0; j < linelength - 4; ) { |
161 | if (y + 1 > y_end || u > u_end || v > v_end) { |
162 | av_frame_set_decode_error_flags(frame, FF_DECODE_ERROR_INVALID_BITSTREAM); |
163 | av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n"); |
164 | break; |
165 | } |
166 | if ((src[j] & 1) && header[28] == COMPRESSED) { |
167 | // Skip amount of pixels and move forward one byte |
168 | skip = src[j] >> 1; |
169 | y += skip; |
170 | u += skip >> 1; |
171 | v += skip >> 1; |
172 | j++; |
173 | } else { |
174 | // Set image data as specified and move forward 4 bytes |
175 | *(y++) = src[j]; |
176 | *(u++) = src[j+1]; |
177 | *(y++) = src[j+2]; |
178 | *(v++) = src[j+3]; |
179 | j += 4; |
180 | } |
181 | } |
182 | } |
183 | } |
184 | |
185 | *got_frame = 1; |
186 | if ((ret = av_frame_ref(data, cpia->frame)) < 0) |
187 | return ret; |
188 | |
189 | return avpkt->size; |
190 | } |
191 | |
192 | static av_cold int cpia_decode_init(AVCodecContext *avctx) |
193 | { |
194 | CpiaContext *s = avctx->priv_data; |
195 | |
196 | // output pixel format |
197 | avctx->pix_fmt = AV_PIX_FMT_YUV420P; |
198 | |
199 | /* The default timebase set by the v4l2 demuxer leads to probing which is buggy. |
200 | * Set some reasonable time_base to skip this. |
201 | */ |
202 | if (avctx->time_base.num == 1 && avctx->time_base.den == 1000000) { |
203 | avctx->time_base.num = 1; |
204 | avctx->time_base.den = 60; |
205 | } |
206 | |
207 | s->frame = av_frame_alloc(); |
208 | if (!s->frame) |
209 | return AVERROR(ENOMEM); |
210 | |
211 | return 0; |
212 | } |
213 | |
214 | static av_cold int cpia_decode_end(AVCodecContext *avctx) |
215 | { |
216 | CpiaContext *s = avctx->priv_data; |
217 | |
218 | av_frame_free(&s->frame); |
219 | |
220 | return 0; |
221 | } |
222 | |
223 | AVCodec ff_cpia_decoder = { |
224 | .name = "cpia", |
225 | .long_name = NULL_IF_CONFIG_SMALL("CPiA video format"), |
226 | .type = AVMEDIA_TYPE_VIDEO, |
227 | .id = AV_CODEC_ID_CPIA, |
228 | .priv_data_size = sizeof(CpiaContext), |
229 | .init = cpia_decode_init, |
230 | .close = cpia_decode_end, |
231 | .decode = cpia_decode_frame, |
232 | .capabilities = AV_CODEC_CAP_DR1, |
233 | }; |
234 |