FFmpeg
cpia.c
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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 "libavutil/intreadwrite.h"
26 #include "avcodec.h"
27 #include "codec_internal.h"
28 #include "decode.h"
29 
30 
31 #define FRAME_HEADER_SIZE 64
32 #define MAGIC_0 0x19 /**< First header byte */
33 #define MAGIC_1 0x68 /**< Second header byte */
34 #define SUBSAMPLE_420 0
35 #define SUBSAMPLE_422 1
36 #define YUVORDER_YUYV 0
37 #define YUVORDER_UYVY 1
38 #define NOT_COMPRESSED 0
39 #define COMPRESSED 1
40 #define NO_DECIMATION 0
41 #define DECIMATION_ENAB 1
42 #define EOL 0xfd /**< End Of Line marker */
43 #define EOI 0xff /**< End Of Image marker */
44 
45 
46 typedef struct {
48 } CpiaContext;
49 
50 
51 static int cpia_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
52  int *got_frame, AVPacket* avpkt)
53 {
54  CpiaContext* const cpia = avctx->priv_data;
55  int i,j,ret;
56 
57  const uint8_t *const header = avpkt->data;
58  const uint8_t *src;
59  int src_size;
60  uint16_t linelength;
61  uint8_t skip;
62 
63  AVFrame *frame = cpia->frame;
64  uint8_t *y, *u, *v, *y_end, *u_end, *v_end;
65 
66  // Check header
67  if ( avpkt->size < FRAME_HEADER_SIZE + avctx->height * 3
68  || header[0] != MAGIC_0 || header[1] != MAGIC_1
69  || (header[17] != SUBSAMPLE_420 && header[17] != SUBSAMPLE_422)
70  || (header[18] != YUVORDER_YUYV && header[18] != YUVORDER_UYVY)
71  || (header[28] != NOT_COMPRESSED && header[28] != COMPRESSED)
72  || (header[29] != NO_DECIMATION && header[29] != DECIMATION_ENAB)
73  ) {
74  av_log(avctx, AV_LOG_ERROR, "Invalid header!\n");
75  return AVERROR_INVALIDDATA;
76  }
77 
78  // currently unsupported properties
79  if (header[17] == SUBSAMPLE_422) {
80  avpriv_report_missing_feature(avctx, "4:2:2 subsampling");
81  return AVERROR_PATCHWELCOME;
82  }
83  if (header[18] == YUVORDER_UYVY) {
84  avpriv_report_missing_feature(avctx, "YUV byte order UYVY");
85  return AVERROR_PATCHWELCOME;
86  }
87  if (header[29] == DECIMATION_ENAB) {
88  avpriv_report_missing_feature(avctx, "Decimation");
89  return AVERROR_PATCHWELCOME;
90  }
91 
93  src_size = avpkt->size - FRAME_HEADER_SIZE;
94 
95  if (header[28] == NOT_COMPRESSED) {
98  } else {
101  }
102 
103  // Get buffer filled with previous frame
104  if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
105  return ret;
106 
107 
108  for ( i = 0;
109  i < frame->height;
110  i++, src += linelength, src_size -= linelength
111  ) {
112  // Read line length, two byte little endian
113  linelength = AV_RL16(src);
114  src += 2;
115  src_size -= 2;
116 
117  if (src_size < linelength) {
119  av_log(avctx, AV_LOG_WARNING, "Frame ended unexpectedly!\n");
120  break;
121  }
122  if (src[linelength - 1] != EOL) {
124  av_log(avctx, AV_LOG_WARNING, "Wrong line length %d or line not terminated properly (found 0x%02x)!\n", linelength, src[linelength - 1]);
125  break;
126  }
127 
128  /* Update the data pointers. Y data is on every line.
129  * U and V data on every second line
130  */
131  y = &frame->data[0][i * frame->linesize[0]];
132  u = &frame->data[1][(i >> 1) * frame->linesize[1]];
133  v = &frame->data[2][(i >> 1) * frame->linesize[2]];
134  y_end = y + frame->linesize[0] - 1;
135  u_end = u + frame->linesize[1] - 1;
136  v_end = v + frame->linesize[2] - 1;
137 
138  if ((i & 1) && header[17] == SUBSAMPLE_420) {
139  /* We are on an odd line and 420 subsample is used.
140  * On this line only Y values are specified, one per pixel.
141  */
142  for (j = 0; j < linelength - 1; j++) {
143  if (y > y_end) {
145  av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n");
146  break;
147  }
148  if ((src[j] & 1) && header[28] == COMPRESSED) {
149  /* It seems that odd lines are always uncompressed, but
150  * we do it according to specification anyways.
151  */
152  skip = src[j] >> 1;
153  y += skip;
154  } else {
155  *(y++) = src[j];
156  }
157  }
158  } else if (header[17] == SUBSAMPLE_420) {
159  /* We are on an even line and 420 subsample is used.
160  * On this line each pair of pixels is described by four bytes.
161  */
162  for (j = 0; j < linelength - 4; ) {
163  if (y + 1 > y_end || u > u_end || v > v_end) {
165  av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n");
166  break;
167  }
168  if ((src[j] & 1) && header[28] == COMPRESSED) {
169  // Skip amount of pixels and move forward one byte
170  skip = src[j] >> 1;
171  y += skip;
172  u += skip >> 1;
173  v += skip >> 1;
174  j++;
175  } else {
176  // Set image data as specified and move forward 4 bytes
177  *(y++) = src[j];
178  *(u++) = src[j+1];
179  *(y++) = src[j+2];
180  *(v++) = src[j+3];
181  j += 4;
182  }
183  }
184  }
185  }
186 
187  *got_frame = 1;
188  if ((ret = av_frame_ref(rframe, cpia->frame)) < 0)
189  return ret;
190 
191  return avpkt->size;
192 }
193 
195 {
196  CpiaContext *s = avctx->priv_data;
197 
198  // output pixel format
199  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
200 
201  s->frame = av_frame_alloc();
202  if (!s->frame)
203  return AVERROR(ENOMEM);
204 
205  return 0;
206 }
207 
209 {
210  CpiaContext *s = avctx->priv_data;
211 
212  av_frame_free(&s->frame);
213 
214  return 0;
215 }
216 
218  .p.name = "cpia",
219  CODEC_LONG_NAME("CPiA video format"),
220  .p.type = AVMEDIA_TYPE_VIDEO,
221  .p.id = AV_CODEC_ID_CPIA,
222  .priv_data_size = sizeof(CpiaContext),
224  .close = cpia_decode_end,
226  .p.capabilities = AV_CODEC_CAP_DR1,
227 };
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
u
#define u(width, name, range_min, range_max)
Definition: cbs_h2645.c:250
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:88
NOT_COMPRESSED
#define NOT_COMPRESSED
Definition: cpia.c:38
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
AVPacket::data
uint8_t * data
Definition: packet.h:522
CpiaContext::frame
AVFrame * frame
Definition: cpia.c:47
SUBSAMPLE_420
#define SUBSAMPLE_420
Definition: cpia.c:34
FFCodec
Definition: codec_internal.h:127
MAGIC_1
#define MAGIC_1
Second header byte.
Definition: cpia.c:33
AVFrame::flags
int flags
Frame flags, a combination of AV_FRAME_FLAGS.
Definition: frame.h:612
YUVORDER_YUYV
#define YUVORDER_YUYV
Definition: cpia.c:36
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:361
cpia_decode_init
static av_cold int cpia_decode_init(AVCodecContext *avctx)
Definition: cpia.c:194
CpiaContext
Definition: cpia.c:46
cpia_decode_frame
static int cpia_decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)
Definition: cpia.c:51
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:76
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
AV_FRAME_FLAG_KEY
#define AV_FRAME_FLAG_KEY
A flag to mark frames that are keyframes.
Definition: frame.h:591
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:287
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
DECIMATION_ENAB
#define DECIMATION_ENAB
Definition: cpia.c:41
decode.h
AV_RL16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:94
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:73
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:272
frame
static AVFrame * frame
Definition: demux_decode.c:54
FF_DECODE_ERROR_INVALID_BITSTREAM
#define FF_DECODE_ERROR_INVALID_BITSTREAM
Definition: frame.h:668
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
AV_CODEC_ID_CPIA
@ AV_CODEC_ID_CPIA
Definition: codec_id.h:261
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:279
NO_DECIMATION
#define NO_DECIMATION
Definition: cpia.c:40
YUVORDER_UYVY
#define YUVORDER_UYVY
Definition: cpia.c:37
FRAME_HEADER_SIZE
#define FRAME_HEADER_SIZE
Definition: cpia.c:31
ff_cpia_decoder
const FFCodec ff_cpia_decoder
Definition: cpia.c:217
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:442
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:365
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:523
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:312
codec_internal.h
SUBSAMPLE_422
#define SUBSAMPLE_422
Definition: cpia.c:35
avpriv_report_missing_feature
void avpriv_report_missing_feature(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
header
static const uint8_t header[24]
Definition: sdr2.c:68
cpia_decode_end
static av_cold int cpia_decode_end(AVCodecContext *avctx)
Definition: cpia.c:208
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:255
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
AVCodecContext::height
int height
Definition: avcodec.h:618
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:657
avcodec.h
ff_reget_buffer
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:1677
AVFrame::decode_error_flags
int decode_error_flags
decode error flags of the frame, set to a combination of FF_DECODE_ERROR_xxx flags if the decoder pro...
Definition: frame.h:667
ret
ret
Definition: filter_design.txt:187
AVCodecContext
main external API structure.
Definition: avcodec.h:445
AVFrame::height
int height
Definition: frame.h:412
EOL
#define EOL
End Of Line marker.
Definition: cpia.c:42
COMPRESSED
#define COMPRESSED
Definition: cpia.c:39
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:280
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:472
AVPacket
This structure stores compressed data.
Definition: packet.h:499
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
MAGIC_0
#define MAGIC_0
First header byte.
Definition: cpia.c:32
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:385
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
skip
static void BS_FUNC() skip(BSCTX *bc, unsigned int n)
Skip n bits in the buffer.
Definition: bitstream_template.h:375