Libav
yuv4mpegdec.c
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1 /*
2  * YUV4MPEG demuxer
3  * Copyright (c) 2001, 2002, 2003 Fabrice Bellard
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "avformat.h"
23 #include "internal.h"
24 #include "yuv4mpeg.h"
25 
26 /* Header size increased to allow room for optional flags */
27 #define MAX_YUV4_HEADER 80
28 #define MAX_FRAME_HEADER 80
29 
31 {
32  char header[MAX_YUV4_HEADER + 10]; // Include headroom for
33  // the longest option
34  char *tokstart, *tokend, *header_end;
35  int i;
36  AVIOContext *pb = s->pb;
37  int width = -1, height = -1, raten = 0,
38  rated = 0, aspectn = 0, aspectd = 0;
40  enum AVChromaLocation chroma_sample_location = AVCHROMA_LOC_UNSPECIFIED;
41  AVStream *st;
42  enum AVFieldOrder field_order;
43 
44  for (i = 0; i < MAX_YUV4_HEADER; i++) {
45  header[i] = avio_r8(pb);
46  if (header[i] == '\n') {
47  header[i + 1] = 0x20; // Add a space after last option.
48  // Makes parsing "444" vs "444alpha" easier.
49  header[i + 2] = 0;
50  break;
51  }
52  }
53  if (i == MAX_YUV4_HEADER)
54  return -1;
55  if (strncmp(header, Y4M_MAGIC, strlen(Y4M_MAGIC)))
56  return -1;
57 
58  header_end = &header[i + 1]; // Include space
59  for (tokstart = &header[strlen(Y4M_MAGIC) + 1];
60  tokstart < header_end; tokstart++) {
61  if (*tokstart == 0x20)
62  continue;
63  switch (*tokstart++) {
64  case 'W': // Width. Required.
65  width = strtol(tokstart, &tokend, 10);
66  tokstart = tokend;
67  break;
68  case 'H': // Height. Required.
69  height = strtol(tokstart, &tokend, 10);
70  tokstart = tokend;
71  break;
72  case 'C': // Color space
73  if (strncmp("420jpeg", tokstart, 7) == 0) {
74  pix_fmt = AV_PIX_FMT_YUV420P;
75  chroma_sample_location = AVCHROMA_LOC_CENTER;
76  } else if (strncmp("420mpeg2", tokstart, 8) == 0) {
77  pix_fmt = AV_PIX_FMT_YUV420P;
78  chroma_sample_location = AVCHROMA_LOC_LEFT;
79  } else if (strncmp("420paldv", tokstart, 8) == 0) {
80  pix_fmt = AV_PIX_FMT_YUV420P;
81  chroma_sample_location = AVCHROMA_LOC_TOPLEFT;
82  } else if (strncmp("420", tokstart, 3) == 0) {
83  pix_fmt = AV_PIX_FMT_YUV420P;
84  chroma_sample_location = AVCHROMA_LOC_CENTER;
85  } else if (strncmp("411", tokstart, 3) == 0)
86  pix_fmt = AV_PIX_FMT_YUV411P;
87  else if (strncmp("422", tokstart, 3) == 0)
88  pix_fmt = AV_PIX_FMT_YUV422P;
89  else if (strncmp("444alpha", tokstart, 8) == 0 ) {
90  av_log(s, AV_LOG_ERROR, "Cannot handle 4:4:4:4 "
91  "YUV4MPEG stream.\n");
92  return -1;
93  } else if (strncmp("444", tokstart, 3) == 0)
94  pix_fmt = AV_PIX_FMT_YUV444P;
95  else if (strncmp("mono", tokstart, 4) == 0) {
96  pix_fmt = AV_PIX_FMT_GRAY8;
97  } else {
98  av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains an unknown "
99  "pixel format.\n");
100  return -1;
101  }
102  while (tokstart < header_end && *tokstart != 0x20)
103  tokstart++;
104  break;
105  case 'I': // Interlace type
106  switch (*tokstart++){
107  case '?':
108  field_order = AV_FIELD_UNKNOWN;
109  break;
110  case 'p':
111  field_order = AV_FIELD_PROGRESSIVE;
112  break;
113  case 't':
114  field_order = AV_FIELD_TT;
115  break;
116  case 'b':
117  field_order = AV_FIELD_BB;
118  break;
119  case 'm':
120  av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains mixed "
121  "interlaced and non-interlaced frames.\n");
122  return -1;
123  default:
124  av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
125  return -1;
126  }
127  break;
128  case 'F': // Frame rate
129  sscanf(tokstart, "%d:%d", &raten, &rated); // 0:0 if unknown
130  while (tokstart < header_end && *tokstart != 0x20)
131  tokstart++;
132  break;
133  case 'A': // Pixel aspect
134  sscanf(tokstart, "%d:%d", &aspectn, &aspectd); // 0:0 if unknown
135  while (tokstart < header_end && *tokstart != 0x20)
136  tokstart++;
137  break;
138  case 'X': // Vendor extensions
139  if (strncmp("YSCSS=", tokstart, 6) == 0) {
140  // Older nonstandard pixel format representation
141  tokstart += 6;
142  if (strncmp("420JPEG", tokstart, 7) == 0)
143  alt_pix_fmt = AV_PIX_FMT_YUV420P;
144  else if (strncmp("420MPEG2", tokstart, 8) == 0)
145  alt_pix_fmt = AV_PIX_FMT_YUV420P;
146  else if (strncmp("420PALDV", tokstart, 8) == 0)
147  alt_pix_fmt = AV_PIX_FMT_YUV420P;
148  else if (strncmp("411", tokstart, 3) == 0)
149  alt_pix_fmt = AV_PIX_FMT_YUV411P;
150  else if (strncmp("422", tokstart, 3) == 0)
151  alt_pix_fmt = AV_PIX_FMT_YUV422P;
152  else if (strncmp("444", tokstart, 3) == 0)
153  alt_pix_fmt = AV_PIX_FMT_YUV444P;
154  }
155  while (tokstart < header_end && *tokstart != 0x20)
156  tokstart++;
157  break;
158  }
159  }
160 
161  if (width == -1 || height == -1) {
162  av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
163  return -1;
164  }
165 
166  if (pix_fmt == AV_PIX_FMT_NONE) {
167  if (alt_pix_fmt == AV_PIX_FMT_NONE)
168  pix_fmt = AV_PIX_FMT_YUV420P;
169  else
170  pix_fmt = alt_pix_fmt;
171  }
172 
173  if (raten <= 0 || rated <= 0) {
174  // Frame rate unknown
175  raten = 25;
176  rated = 1;
177  }
178 
179  if (aspectn == 0 && aspectd == 0) {
180  // Pixel aspect unknown
181  aspectd = 1;
182  }
183 
184  st = avformat_new_stream(s, NULL);
185  if (!st)
186  return AVERROR(ENOMEM);
187  st->codec->width = width;
188  st->codec->height = height;
189  av_reduce(&raten, &rated, raten, rated, (1UL << 31) - 1);
190  avpriv_set_pts_info(st, 64, rated, raten);
191  st->avg_frame_rate = av_inv_q(st->time_base);
192  st->codec->pix_fmt = pix_fmt;
195  st->sample_aspect_ratio = (AVRational){ aspectn, aspectd };
196  st->codec->chroma_sample_location = chroma_sample_location;
197  st->codec->field_order = field_order;
198 
199  return 0;
200 }
201 
203 {
204  int i;
205  char header[MAX_FRAME_HEADER+1];
206  int packet_size, width, height, ret;
207  AVStream *st = s->streams[0];
208 
209  for (i = 0; i < MAX_FRAME_HEADER; i++) {
210  header[i] = avio_r8(s->pb);
211  if (header[i] == '\n') {
212  header[i + 1] = 0;
213  break;
214  }
215  }
216  if (s->pb->error)
217  return s->pb->error;
218  else if (s->pb->eof_reached)
219  return AVERROR_EOF;
220  else if (i == MAX_FRAME_HEADER)
221  return AVERROR_INVALIDDATA;
222 
223  if (strncmp(header, Y4M_FRAME_MAGIC, strlen(Y4M_FRAME_MAGIC)))
224  return AVERROR_INVALIDDATA;
225 
226  width = st->codec->width;
227  height = st->codec->height;
228 
229  packet_size = avpicture_get_size(st->codec->pix_fmt, width, height);
230  if (packet_size < 0)
231  return packet_size;
232 
233  ret = av_get_packet(s->pb, pkt, packet_size);
234  if (ret < 0)
235  return ret;
236  else if (ret != packet_size)
237  return s->pb->eof_reached ? AVERROR_EOF : AVERROR(EIO);
238 
239  pkt->stream_index = 0;
240  return 0;
241 }
242 
243 static int yuv4_probe(AVProbeData *pd)
244 {
245  /* check file header */
246  if (strncmp(pd->buf, Y4M_MAGIC, sizeof(Y4M_MAGIC) - 1) == 0)
247  return AVPROBE_SCORE_MAX;
248  else
249  return 0;
250 }
251 
253  .name = "yuv4mpegpipe",
254  .long_name = NULL_IF_CONFIG_SMALL("YUV4MPEG pipe"),
255  .read_probe = yuv4_probe,
256  .read_header = yuv4_read_header,
257  .read_packet = yuv4_read_packet,
258  .extensions = "y4m",
259 };
Bytestream IO Context.
Definition: avio.h:68
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
mpeg2/4, h264 default
Definition: pixfmt.h:378
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:70
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:2829
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:769
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1254
Format I/O context.
Definition: avformat.h:922
#define Y4M_FRAME_MAGIC
Definition: yuv4mpeg.h:25
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2521
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:990
#define AVERROR_EOF
End of file.
Definition: error.h:51
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:117
enum AVChromaLocation chroma_sample_location
This defines the location of chroma samples.
Definition: avcodec.h:1773
#define Y4M_MAGIC
Definition: yuv4mpeg.h:24
static int yuv4_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: yuv4mpegdec.c:202
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
AVRational avg_frame_rate
Average framerate.
Definition: avformat.h:780
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:69
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:443
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:718
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:397
int width
picture width / height.
Definition: avcodec.h:1224
enum AVPixelFormat pix_fmt
Definition: movenc.c:843
Stream structure.
Definition: avformat.h:699
NULL
Definition: eval.c:55
static int width
Definition: utils.c:156
enum AVMediaType codec_type
Definition: avcodec.h:1058
enum AVCodecID codec_id
Definition: avcodec.h:1067
static int yuv4_read_header(AVFormatContext *s)
Definition: yuv4mpegdec.c:30
AVIOContext * pb
I/O context.
Definition: avformat.h:964
rational number numerator/denominator
Definition: rational.h:43
AVFieldOrder
Definition: avcodec.h:1034
int error
contains the error code or 0 if no error happened
Definition: avio.h:102
This structure contains the data a format has to probe a file.
Definition: avformat.h:395
static av_always_inline AVRational av_inv_q(AVRational q)
Invert a rational.
Definition: rational.h:122
int height
Definition: gxfenc.c:72
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:404
Main libavformat public API header.
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:65
Y , 8bpp.
Definition: pixfmt.h:73
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
Definition: pixfmt.h:72
int eof_reached
true if eof reached
Definition: avio.h:96
int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height)
Calculate the size in bytes that a picture of the given width and height would occupy if stored in th...
Definition: avpicture.c:85
AVInputFormat ff_yuv4mpegpipe_demuxer
Definition: yuv4mpegdec.c:252
static int yuv4_probe(AVProbeData *pd)
Definition: yuv4mpegdec.c:243
enum AVFieldOrder field_order
Field order.
Definition: avcodec.h:1788
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:525
AVChromaLocation
Location of chroma samples.
Definition: pixfmt.h:376
mpeg1, jpeg, h263
Definition: pixfmt.h:379
int stream_index
Definition: avcodec.h:975
#define MAX_YUV4_HEADER
Definition: yuv4mpegdec.c:27
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:741
AVPixelFormat
Pixel format.
Definition: pixfmt.h:63
This structure stores compressed data.
Definition: avcodec.h:950
#define MAX_FRAME_HEADER
Definition: yuv4mpegdec.c:28