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 "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 
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)) < 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 };
#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:295
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
#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:1481
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1778
#define src
Definition: vp8dsp.c:254
AVCodec.
Definition: avcodec.h:3492
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
#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:1691
#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:189
#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:443
#define u(width, name, range_min, range_max)
Definition: cbs_h2645.c:252
uint8_t * data
Definition: avcodec.h:1480
#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 i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define YUVORDER_YUYV
Definition: cpia.c:35
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
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:186
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:2015
#define DECIMATION_ENAB
Definition: cpia.c:40
const char * name
Name of the codec implementation.
Definition: avcodec.h:3499
#define SUBSAMPLE_420
Definition: cpia.c:33
static av_cold int cpia_decode_end(AVCodecContext *avctx)
Definition: cpia.c:214
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:378
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
#define s(width, name)
Definition: cbs_vp9.c:257
#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:326
#define NO_DECIMATION
Definition: cpia.c:39
main external API structure.
Definition: avcodec.h:1568
#define COMPRESSED
Definition: cpia.c:38
AVCodec ff_cpia_decoder
Definition: cpia.c:223
#define FF_DECODE_ERROR_INVALID_BITSTREAM
Definition: frame.h:591
AVFrame * frame
Definition: cpia.c:46
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:590
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:309
#define YUVORDER_UYVY
Definition: cpia.c:36
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
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:1595
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:373
int height
Definition: frame.h:353
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
This structure stores compressed data.
Definition: avcodec.h:1457
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:984
Predicted.
Definition: avutil.h:275