FFmpeg  4.4.6
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 "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 {
47 } CpiaContext;
48 
49 
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 + avctx->height * 3
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 
92  src_size = avpkt->size - FRAME_HEADER_SIZE;
93 
94  if (header[28] == NOT_COMPRESSED) {
96  frame->key_frame = 1;
97  } else {
99  frame->key_frame = 0;
100  }
101 
102  // Get buffer filled with previous frame
103  if ((ret = ff_reget_buffer(avctx, frame, 0)) < 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  src_size -= 2;
115 
116  if (src_size < linelength) {
118  av_log(avctx, AV_LOG_WARNING, "Frame ended unexpectedly!\n");
119  break;
120  }
121  if (src[linelength - 1] != EOL) {
123  av_log(avctx, AV_LOG_WARNING, "Wrong line length %d or line not terminated properly (found 0x%02x)!\n", linelength, src[linelength - 1]);
124  break;
125  }
126 
127  /* Update the data pointers. Y data is on every line.
128  * U and V data on every second line
129  */
130  y = &frame->data[0][i * frame->linesize[0]];
131  u = &frame->data[1][(i >> 1) * frame->linesize[1]];
132  v = &frame->data[2][(i >> 1) * frame->linesize[2]];
133  y_end = y + frame->linesize[0] - 1;
134  u_end = u + frame->linesize[1] - 1;
135  v_end = v + frame->linesize[2] - 1;
136 
137  if ((i & 1) && header[17] == SUBSAMPLE_420) {
138  /* We are on an odd line and 420 subsample is used.
139  * On this line only Y values are specified, one per pixel.
140  */
141  for (j = 0; j < linelength - 1; j++) {
142  if (y > y_end) {
144  av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n");
145  break;
146  }
147  if ((src[j] & 1) && header[28] == COMPRESSED) {
148  /* It seems that odd lines are always uncompressed, but
149  * we do it according to specification anyways.
150  */
151  skip = src[j] >> 1;
152  y += skip;
153  } else {
154  *(y++) = src[j];
155  }
156  }
157  } else if (header[17] == SUBSAMPLE_420) {
158  /* We are on an even line and 420 subsample is used.
159  * On this line each pair of pixels is described by four bytes.
160  */
161  for (j = 0; j < linelength - 4; ) {
162  if (y + 1 > y_end || u > u_end || v > v_end) {
164  av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n");
165  break;
166  }
167  if ((src[j] & 1) && header[28] == COMPRESSED) {
168  // Skip amount of pixels and move forward one byte
169  skip = src[j] >> 1;
170  y += skip;
171  u += skip >> 1;
172  v += skip >> 1;
173  j++;
174  } else {
175  // Set image data as specified and move forward 4 bytes
176  *(y++) = src[j];
177  *(u++) = src[j+1];
178  *(y++) = src[j+2];
179  *(v++) = src[j+3];
180  j += 4;
181  }
182  }
183  }
184  }
185 
186  *got_frame = 1;
187  if ((ret = av_frame_ref(data, cpia->frame)) < 0)
188  return ret;
189 
190  return avpkt->size;
191 }
192 
194 {
195  CpiaContext *s = avctx->priv_data;
196 
197  // output pixel format
198  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
199 
200  /* The default timebase set by the v4l2 demuxer leads to probing which is buggy.
201  * Set some reasonable time_base to skip this.
202  */
203  if (avctx->time_base.num == 1 && avctx->time_base.den == 1000000) {
204  avctx->time_base.num = 1;
205  avctx->time_base.den = 60;
206  }
207 
208  s->frame = av_frame_alloc();
209  if (!s->frame)
210  return AVERROR(ENOMEM);
211 
212  return 0;
213 }
214 
216 {
217  CpiaContext *s = avctx->priv_data;
218 
219  av_frame_free(&s->frame);
220 
221  return 0;
222 }
223 
225  .name = "cpia",
226  .long_name = NULL_IF_CONFIG_SMALL("CPiA video format"),
227  .type = AVMEDIA_TYPE_VIDEO,
228  .id = AV_CODEC_ID_CPIA,
229  .priv_data_size = sizeof(CpiaContext),
231  .close = cpia_decode_end,
233  .capabilities = AV_CODEC_CAP_DR1,
234  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
235 };
#define av_cold
Definition: attributes.h:88
uint8_t
Libavcodec external API header.
#define AV_RL16
Definition: intreadwrite.h:42
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
#define u(width, name, range_min, range_max)
Definition: cbs_h2645.c:264
#define s(width, name)
Definition: cbs_vp9.c:257
AVCodec ff_cpia_decoder
Definition: cpia.c:224
#define SUBSAMPLE_420
Definition: cpia.c:33
#define YUVORDER_YUYV
Definition: cpia.c:35
#define SUBSAMPLE_422
Definition: cpia.c:34
#define EOL
End Of Line marker.
Definition: cpia.c:41
#define FRAME_HEADER_SIZE
Definition: cpia.c:30
#define MAGIC_0
First header byte.
Definition: cpia.c:31
static av_cold int cpia_decode_init(AVCodecContext *avctx)
Definition: cpia.c:193
#define YUVORDER_UYVY
Definition: cpia.c:36
#define NOT_COMPRESSED
Definition: cpia.c:37
#define COMPRESSED
Definition: cpia.c:38
static int cpia_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: cpia.c:50
#define MAGIC_1
Second header byte.
Definition: cpia.c:32
#define NO_DECIMATION
Definition: cpia.c:39
static av_cold int cpia_decode_end(AVCodecContext *avctx)
Definition: cpia.c:215
#define DECIMATION_ENAB
Definition: cpia.c:40
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:2007
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
static AVFrame * frame
#define FF_DECODE_ERROR_INVALID_BITSTREAM
Definition: frame.h:614
bitstream reader API header.
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
@ AV_CODEC_ID_CPIA
Definition: codec_id.h:260
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR(e)
Definition: error.h:43
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:443
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:190
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:275
int i
Definition: input.c:407
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:41
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
void avpriv_report_missing_feature(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
const char data[16]
Definition: mxf.c:142
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
static const uint8_t header[24]
Definition: sdr2.c:67
main external API structure.
Definition: avcodec.h:536
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:746
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avcodec.h:659
void * priv_data
Definition: avcodec.h:563
AVCodec.
Definition: codec.h:197
const char * name
Name of the codec implementation.
Definition: codec.h:204
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:332
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:396
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:613
int height
Definition: frame.h:376
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:349
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:401
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
int num
Numerator.
Definition: rational.h:59
int den
Denominator.
Definition: rational.h:60
AVFrame * frame
Definition: cpia.c:46
#define av_log(a,...)
#define src
Definition: vp8dsp.c:255