3 * Copyright (c) 2010 Hans de Goede <hdegoede@redhat.com>
5 * This decoder is based on the LGPL code available at
6 * https://v4l4j.googlecode.com/svn/v4l4j/trunk/libvideo/libv4lconvert/cpia1.c
8 * This file is part of FFmpeg.
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.
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.
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
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
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 */
50 static int cpia_decode_frame(AVCodecContext
*avctx
,
51 void *data
, int *got_frame
, AVPacket
* avpkt
)
53 CpiaContext
* const cpia
= avctx
->priv_data
;
56 uint8_t* const header
= avpkt
->data
;
62 AVFrame
*frame
= cpia
->frame
;
63 uint8_t *y
, *u
, *v
, *y_end
, *u_end
, *v_end
;
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
)
73 av_log(avctx
, AV_LOG_ERROR
, "Invalid header!\n");
74 return AVERROR_INVALIDDATA
;
77 // currently unsupported properties
78 if (header
[17] == SUBSAMPLE_422
) {
79 avpriv_report_missing_feature(avctx
, "4:2:2 subsampling");
80 return AVERROR_PATCHWELCOME
;
82 if (header
[18] == YUVORDER_UYVY
) {
83 avpriv_report_missing_feature(avctx
, "YUV byte order UYVY");
84 return AVERROR_PATCHWELCOME
;
86 if (header
[29] == DECIMATION_ENAB
) {
87 avpriv_report_missing_feature(avctx
, "Decimation");
88 return AVERROR_PATCHWELCOME
;
91 src
= header
+ FRAME_HEADER_SIZE
;
92 src_size
= avpkt
->size
- FRAME_HEADER_SIZE
;
94 if (header
[28] == NOT_COMPRESSED
) {
95 frame
->pict_type
= AV_PICTURE_TYPE_I
;
98 frame
->pict_type
= AV_PICTURE_TYPE_P
;
102 // Get buffer filled with previous frame
103 if ((ret
= ff_reget_buffer(avctx
, frame
)) < 0)
109 i
++, src
+= linelength
, src_size
-= linelength
111 // Read line length, two byte little endian
112 linelength
= AV_RL16(src
);
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");
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]);
126 /* Update the data pointers. Y data is on every line.
127 * U and V data on every second line
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;
136 if ((i
& 1) && header
[17] == SUBSAMPLE_420
) {
137 /* We are on a odd line and 420 subsample is used.
138 * On this line only Y values are specified, one per pixel.
140 for (j
= 0; j
< linelength
- 1; j
++) {
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");
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.
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.
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");
166 if ((src
[j
] & 1) && header
[28] == COMPRESSED
) {
167 // Skip amount of pixels and move forward one byte
174 // Set image data as specified and move forward 4 bytes
186 if ((ret
= av_frame_ref(data
, cpia
->frame
)) < 0)
192 static av_cold
int cpia_decode_init(AVCodecContext
*avctx
)
194 CpiaContext
*s
= avctx
->priv_data
;
196 // output pixel format
197 avctx
->pix_fmt
= AV_PIX_FMT_YUV420P
;
199 /* The default timebase set by the v4l2 demuxer leads to probing which is buggy.
200 * Set some reasonable time_base to skip this.
202 if (avctx
->time_base
.num
== 1 && avctx
->time_base
.den
== 1000000) {
203 avctx
->time_base
.num
= 1;
204 avctx
->time_base
.den
= 60;
207 s
->frame
= av_frame_alloc();
209 return AVERROR(ENOMEM
);
214 static av_cold
int cpia_decode_end(AVCodecContext
*avctx
)
216 CpiaContext
*s
= avctx
->priv_data
;
218 av_frame_free(&s
->frame
);
223 AVCodec ff_cpia_decoder
= {
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
= CODEC_CAP_DR1
,