FFmpeg  4.3
mxg.c
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1 /*
2  * MxPEG clip file demuxer
3  * Copyright (c) 2010 Anatoly Nenashev
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
23 #include "libavutil/internal.h"
24 #include "libavutil/intreadwrite.h"
25 #include "libavcodec/mjpeg.h"
26 #include "avformat.h"
27 #include "internal.h"
28 #include "avio.h"
29 
30 #define DEFAULT_PACKET_SIZE 1024
31 #define OVERREAD_SIZE 3
32 
33 typedef struct MXGContext {
37  unsigned int buffer_size;
38  int64_t dts;
39  unsigned int cache_size;
40 } MXGContext;
41 
43 {
45  MXGContext *mxg = s->priv_data;
46 
47  /* video parameters will be extracted from the compressed bitstream */
49  if (!video_st)
50  return AVERROR(ENOMEM);
53  avpriv_set_pts_info(video_st, 64, 1, 1000000);
54 
56  if (!audio_st)
57  return AVERROR(ENOMEM);
62  audio_st->codecpar->sample_rate = 8000;
65  avpriv_set_pts_info(audio_st, 64, 1, 1000000);
66 
67  mxg->soi_ptr = mxg->buffer_ptr = mxg->buffer = 0;
68  mxg->buffer_size = 0;
69  mxg->dts = AV_NOPTS_VALUE;
70  mxg->cache_size = 0;
71 
72  return 0;
73 }
74 
76 {
77  for (; p < end - 3; p += 4) {
78  uint32_t x = AV_RN32(p);
79 
80  if (x & (~(x+0x01010101)) & 0x80808080) {
81  if (p[0] == 0xff) {
82  return p;
83  } else if (p[1] == 0xff) {
84  return p+1;
85  } else if (p[2] == 0xff) {
86  return p+2;
87  } else if (p[3] == 0xff) {
88  return p+3;
89  }
90  }
91  }
92 
93  for (; p < end; ++p) {
94  if (*p == 0xff) return p;
95  }
96 
97  return end;
98 }
99 
100 static int mxg_update_cache(AVFormatContext *s, unsigned int cache_size)
101 {
102  MXGContext *mxg = s->priv_data;
103  unsigned int current_pos = mxg->buffer_ptr - mxg->buffer;
104  unsigned int soi_pos;
105  uint8_t *buffer;
106  int ret;
107 
108  /* reallocate internal buffer */
109  if (current_pos > current_pos + cache_size)
110  return AVERROR(ENOMEM);
111  soi_pos = mxg->soi_ptr - mxg->buffer;
113  current_pos + cache_size +
115  if (!buffer)
116  return AVERROR(ENOMEM);
117  mxg->buffer = buffer;
118  mxg->buffer_ptr = mxg->buffer + current_pos;
119  if (mxg->soi_ptr) mxg->soi_ptr = mxg->buffer + soi_pos;
120 
121  /* get data */
122  ret = avio_read(s->pb, mxg->buffer_ptr + mxg->cache_size,
123  cache_size - mxg->cache_size);
124  if (ret < 0)
125  return ret;
126 
127  mxg->cache_size += ret;
128 
129  return ret;
130 }
131 
133 {
134  int ret;
135  unsigned int size;
136  uint8_t *startmarker_ptr, *end, *search_end, marker;
137  MXGContext *mxg = s->priv_data;
138 
139  while (!avio_feof(s->pb) && !s->pb->error){
140  if (mxg->cache_size <= OVERREAD_SIZE) {
141  /* update internal buffer */
143  if (ret < 0)
144  return ret;
145  }
146  end = mxg->buffer_ptr + mxg->cache_size;
147 
148  /* find start marker - 0xff */
149  if (mxg->cache_size > OVERREAD_SIZE) {
150  search_end = end - OVERREAD_SIZE;
151  startmarker_ptr = mxg_find_startmarker(mxg->buffer_ptr, search_end);
152  } else {
153  search_end = end;
154  startmarker_ptr = mxg_find_startmarker(mxg->buffer_ptr, search_end);
155  if (startmarker_ptr >= search_end - 1 ||
156  *(startmarker_ptr + 1) != EOI) break;
157  }
158 
159  if (startmarker_ptr != search_end) { /* start marker found */
160  marker = *(startmarker_ptr + 1);
161  mxg->buffer_ptr = startmarker_ptr + 2;
162  mxg->cache_size = end - mxg->buffer_ptr;
163 
164  if (marker == SOI) {
165  mxg->soi_ptr = startmarker_ptr;
166  } else if (marker == EOI) {
167  if (!mxg->soi_ptr) {
168  av_log(s, AV_LOG_WARNING, "Found EOI before SOI, skipping\n");
169  continue;
170  }
171 
172  size = mxg->buffer_ptr - mxg->soi_ptr;
174  if (ret < 0)
175  return ret;
176  memcpy(pkt->data, mxg->soi_ptr, size);
177 
178  pkt->pts = pkt->dts = mxg->dts;
179  pkt->stream_index = 0;
180 
181  if (mxg->soi_ptr - mxg->buffer > mxg->cache_size) {
182  if (mxg->cache_size > 0) {
183  memmove(mxg->buffer, mxg->buffer_ptr, mxg->cache_size);
184  }
185 
186  mxg->buffer_ptr = mxg->buffer;
187  }
188  mxg->soi_ptr = 0;
189 
190  return pkt->size;
191  } else if ( (SOF0 <= marker && marker <= SOF15) ||
192  (SOS <= marker && marker <= COM) ) {
193  /* all other markers that start marker segment also contain
194  length value (see specification for JPEG Annex B.1) */
195  size = AV_RB16(mxg->buffer_ptr);
196  if (size < 2)
197  return AVERROR(EINVAL);
198 
199  if (mxg->cache_size < size) {
201  if (ret < 0)
202  return ret;
203  startmarker_ptr = mxg->buffer_ptr - 2;
204  mxg->cache_size = 0;
205  } else {
206  mxg->cache_size -= size;
207  }
208 
209  mxg->buffer_ptr += size;
210 
211  if (marker == APP13 && size >= 16) { /* audio data */
212  ret = av_new_packet(pkt, size - 14);
213  if (ret < 0)
214  return ret;
215  memcpy(pkt->data, startmarker_ptr + 16, size - 14);
216 
217  /* time (GMT) of first sample in usec since 1970, little-endian */
218  pkt->pts = pkt->dts = AV_RL64(startmarker_ptr + 8);
219  pkt->stream_index = 1;
220 
221  if (startmarker_ptr - mxg->buffer > mxg->cache_size) {
222  if (mxg->cache_size > 0) {
223  memcpy(mxg->buffer, mxg->buffer_ptr, mxg->cache_size);
224  }
225  mxg->buffer_ptr = mxg->buffer;
226  }
227 
228  return pkt->size;
229  } else if (marker == COM && size >= 18 &&
230  !strncmp(startmarker_ptr + 4, "MXF", 3)) {
231  /* time (GMT) of video frame in usec since 1970, little-endian */
232  mxg->dts = AV_RL64(startmarker_ptr + 12);
233  }
234  }
235  } else {
236  /* start marker not found */
237  mxg->buffer_ptr = search_end;
238  mxg->cache_size = OVERREAD_SIZE;
239  }
240  }
241 
242  return AVERROR_EOF;
243 }
244 
245 static int mxg_close(struct AVFormatContext *s)
246 {
247  MXGContext *mxg = s->priv_data;
248  av_freep(&mxg->buffer);
249  return 0;
250 }
251 
253  .name = "mxg",
254  .long_name = NULL_IF_CONFIG_SMALL("MxPEG clip"),
255  .priv_data_size = sizeof(MXGContext),
259  .extensions = "mxg",
260 };
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
mjpeg.h
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
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4519
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
MXGContext::buffer_size
unsigned int buffer_size
Definition: mxg.c:37
SOS
@ SOS
Definition: mjpeg.h:72
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
SOF0
@ SOF0
Definition: mjpeg.h:39
AV_CH_LAYOUT_MONO
#define AV_CH_LAYOUT_MONO
Definition: channel_layout.h:85
end
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
AVPacket::data
uint8_t * data
Definition: packet.h:355
AV_RB16
#define AV_RB16
Definition: intreadwrite.h:53
mxg_read_header
static int mxg_read_header(AVFormatContext *s)
Definition: mxg.c:42
AV_CODEC_ID_MXPEG
@ AV_CODEC_ID_MXPEG
Definition: codec_id.h:195
MXGContext::buffer
uint8_t * buffer
Definition: mxg.c:34
mxg_update_cache
static int mxg_update_cache(AVFormatContext *s, unsigned int cache_size)
Definition: mxg.c:100
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
mxg_find_startmarker
static uint8_t * mxg_find_startmarker(uint8_t *p, uint8_t *end)
Definition: mxg.c:75
x
FFmpeg Automated Testing Environment ************************************Introduction Using FATE from your FFmpeg source directory Submitting the results to the FFmpeg result aggregation server Uploading new samples to the fate suite FATE makefile targets and variables Makefile targets Makefile variables Examples Introduction **************FATE is an extended regression suite on the client side and a means for results aggregation and presentation on the server side The first part of this document explains how you can use FATE from your FFmpeg source directory to test your ffmpeg binary The second part describes how you can run FATE to submit the results to FFmpeg’s FATE server In any way you can have a look at the publicly viewable FATE results by visiting this as it can be seen if some test on some platform broke with their recent contribution This usually happens on the platforms the developers could not test on The second part of this document describes how you can run FATE to submit your results to FFmpeg’s FATE server If you want to submit your results be sure to check that your combination of OS and compiler is not already listed on the above mentioned website In the third part you can find a comprehensive listing of FATE makefile targets and variables Using FATE from your FFmpeg source directory **********************************************If you want to run FATE on your machine you need to have the samples in place You can get the samples via the build target fate rsync Use this command from the top level source this will cause FATE to fail NOTE To use a custom wrapper to run the pass ‘ target exec’ to ‘configure’ or set the TARGET_EXEC Make variable Submitting the results to the FFmpeg result aggregation server ****************************************************************To submit your results to the server you should run fate through the shell script ‘tests fate sh’ from the FFmpeg sources This script needs to be invoked with a configuration file as its first argument tests fate sh path to fate_config A configuration file template with comments describing the individual configuration variables can be found at ‘doc fate_config sh template’ Create a configuration that suits your based on the configuration template The ‘slot’ configuration variable can be any string that is not yet but it is suggested that you name it adhering to the following pattern ‘ARCH OS COMPILER COMPILER VERSION’ The configuration file itself will be sourced in a shell therefore all shell features may be used This enables you to setup the environment as you need it for your build For your first test runs the ‘fate_recv’ variable should be empty or commented out This will run everything as normal except that it will omit the submission of the results to the server The following files should be present in $workdir as specified in the configuration it may help to try out the ‘ssh’ command with one or more ‘ v’ options You should get detailed output concerning your SSH configuration and the authentication process The only thing left is to automate the execution of the fate sh script and the synchronisation of the samples directory Uploading new samples to the fate suite *****************************************If you need a sample uploaded send a mail to samples request This is for developers who have an account on the fate suite server If you upload new please make sure they are as small as space on each network bandwidth and so on benefit from smaller test cases Also keep in mind older checkouts use existing sample that means in practice generally do not remove or overwrite files as it likely would break older checkouts or releases Also all needed samples for a commit should be ideally before the push If you need an account for frequently uploading samples or you wish to help others by doing that send a mail to ffmpeg devel rsync vauL Duo x
Definition: fate.txt:150
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
APP13
@ APP13
Definition: mjpeg.h:92
AVInputFormat
Definition: avformat.h:636
COM
@ COM
Definition: mjpeg.h:111
av_fast_realloc
void * av_fast_realloc(void *ptr, unsigned int *size, size_t min_size)
Reallocate the given buffer if it is not large enough, otherwise do nothing.
Definition: mem.c:478
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:88
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:641
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
MXGContext::cache_size
unsigned int cache_size
Definition: mxg.c:39
MXGContext::buffer_ptr
uint8_t * buffer_ptr
Definition: mxg.c:35
OVERREAD_SIZE
#define OVERREAD_SIZE
Definition: mxg.c:31
MXGContext::dts
int64_t dts
Definition: mxg.c:38
AVFormatContext
Format I/O context.
Definition: avformat.h:1335
AV_CODEC_ID_PCM_ALAW
@ AV_CODEC_ID_PCM_ALAW
Definition: codec_id.h:308
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1012
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
NULL
#define NULL
Definition: coverity.c:32
AV_RL64
#define AV_RL64
Definition: intreadwrite.h:173
AV_RN32
#define AV_RN32(p)
Definition: intreadwrite.h:364
audio_st
AVStream * audio_st
Definition: movenc.c:59
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
AVPacket::size
int size
Definition: packet.h:356
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:186
MXGContext::soi_ptr
uint8_t * soi_ptr
Definition: mxg.c:36
avpriv_set_pts_info
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:4938
size
int size
Definition: twinvq_data.h:11134
avio.h
video_st
AVStream * video_st
Definition: movenc.c:59
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
SOF15
@ SOF15
Definition: mjpeg.h:54
AVPacket::dts
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:354
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:348
EOI
@ EOI
Definition: mjpeg.h:71
internal.h
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:177
mxg_read_packet
static int mxg_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mxg.c:132
uint8_t
uint8_t
Definition: audio_convert.c:194
MXGContext
Definition: mxg.c:33
ret
ret
Definition: filter_design.txt:187
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVStream
Stream structure.
Definition: avformat.h:865
mxg_close
static int mxg_close(struct AVFormatContext *s)
Definition: mxg.c:245
avformat.h
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: avcodec.h:215
channel_layout.h
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
buffer
the frame and frame reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFrame structures Several references can point to the same frame buffer
Definition: filter_design.txt:49
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:625
AVPacket::stream_index
int stream_index
Definition: packet.h:357
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:102
SOI
@ SOI
Definition: mjpeg.h:70
DEFAULT_PACKET_SIZE
#define DEFAULT_PACKET_SIZE
Definition: mxg.c:30
ff_mxg_demuxer
AVInputFormat ff_mxg_demuxer
Definition: mxg.c:252
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:332
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
AVCodecParameters::channel_layout
uint64_t channel_layout
Audio only.
Definition: codec_par.h:162
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:356