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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
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) {
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)
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) {
117  av_log(avctx, AV_LOG_WARNING, "Frame ended unexpectedly!\n");
118  break;
119  }
120  if (src[linelength - 1] != EOL) {
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) {
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) {
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 
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 
215 {
216  CpiaContext *s = avctx->priv_data;
217 
218  av_frame_free(&s->frame);
219 
220  return 0;
221 }
222 
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),
230  .close = cpia_decode_end,
232  .capabilities = AV_CODEC_CAP_DR1,
233 };
const char * s
Definition: avisynth_c.h:768
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:184
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
#define SUBSAMPLE_422
Definition: cpia.c:34
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int num
Numerator.
Definition: rational.h:59
int size
Definition: avcodec.h:1591
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1887
AVCodec.
Definition: avcodec.h:3573
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
#define EOL
End Of Line marker.
Definition: cpia.c:41
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avcodec.h:1796
#define MAGIC_0
First header byte.
Definition: cpia.c:31
uint8_t
#define av_cold
Definition: attributes.h:82
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:140
#define FRAME_HEADER_SIZE
Definition: cpia.c:30
static int cpia_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: cpia.c:50
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:374
static AVFrame * frame
uint8_t * data
Definition: avcodec.h:1590
#define NOT_COMPRESSED
Definition: cpia.c:37
bitstream reader API header.
static const uint8_t header[24]
Definition: sdr2.c:67
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define YUVORDER_YUYV
Definition: cpia.c:35
#define AVERROR(e)
Definition: error.h:43
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:153
static av_cold int cpia_decode_init(AVCodecContext *avctx)
Definition: cpia.c:192
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
#define DECIMATION_ENAB
Definition: cpia.c:40
const char * name
Name of the codec implementation.
Definition: avcodec.h:3580
#define SUBSAMPLE_420
Definition: cpia.c:33
static av_cold int cpia_decode_end(AVCodecContext *avctx)
Definition: cpia.c:214
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame)
Identical in function to av_frame_make_writable(), except it uses ff_get_buffer() to allocate the buf...
Definition: utils.c:977
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:258
#define src
Definition: vp9dsp.c:530
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:215
#define NO_DECIMATION
Definition: cpia.c:39
main external API structure.
Definition: avcodec.h:1659
#define COMPRESSED
Definition: cpia.c:38
AVCodec ff_cpia_decoder
Definition: cpia.c:223
void av_frame_set_decode_error_flags(AVFrame *frame, int val)
#define FF_DECODE_ERROR_INVALID_BITSTREAM
Definition: frame.h:478
#define u(width,...)
AVFrame * frame
Definition: cpia.c:46
void avpriv_report_missing_feature(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:198
#define YUVORDER_UYVY
Definition: cpia.c:36
static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
Definition: ccaption_dec.c:752
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:62
common internal api header.
#define MAGIC_1
Second header byte.
Definition: cpia.c:32
int den
Denominator.
Definition: rational.h:60
void * priv_data
Definition: avcodec.h:1701
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:253
int height
Definition: frame.h:236
This structure stores compressed data.
Definition: avcodec.h:1567
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:958
Predicted.
Definition: avutil.h:269