FFmpeg
avio_list_dir.c
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1 /*
2  * Copyright (c) 2014 Lukasz Marek
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a copy
5  * of this software and associated documentation files (the "Software"), to deal
6  * in the Software without restriction, including without limitation the rights
7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8  * copies of the Software, and to permit persons to whom the Software is
9  * furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20  * THE SOFTWARE.
21  */
22 
23 #include <libavcodec/avcodec.h>
24 #include <libavformat/avformat.h>
25 #include <libavformat/avio.h>
26 
27 static const char *type_string(int type)
28 {
29  switch (type) {
31  return "<DIR>";
32  case AVIO_ENTRY_FILE:
33  return "<FILE>";
35  return "<BLOCK DEVICE>";
37  return "<CHARACTER DEVICE>";
39  return "<PIPE>";
41  return "<LINK>";
42  case AVIO_ENTRY_SOCKET:
43  return "<SOCKET>";
44  case AVIO_ENTRY_SERVER:
45  return "<SERVER>";
46  case AVIO_ENTRY_SHARE:
47  return "<SHARE>";
49  return "<WORKGROUP>";
50  case AVIO_ENTRY_UNKNOWN:
51  default:
52  break;
53  }
54  return "<UNKNOWN>";
55 }
56 
57 static int list_op(const char *input_dir)
58 {
59  AVIODirEntry *entry = NULL;
61  int cnt, ret;
62  char filemode[4], uid_and_gid[20];
63 
64  if ((ret = avio_open_dir(&ctx, input_dir, NULL)) < 0) {
65  av_log(NULL, AV_LOG_ERROR, "Cannot open directory: %s.\n", av_err2str(ret));
66  goto fail;
67  }
68 
69  cnt = 0;
70  for (;;) {
71  if ((ret = avio_read_dir(ctx, &entry)) < 0) {
72  av_log(NULL, AV_LOG_ERROR, "Cannot list directory: %s.\n", av_err2str(ret));
73  goto fail;
74  }
75  if (!entry)
76  break;
77  if (entry->filemode == -1) {
78  snprintf(filemode, 4, "???");
79  } else {
80  snprintf(filemode, 4, "%3"PRIo64, entry->filemode);
81  }
82  snprintf(uid_and_gid, 20, "%"PRId64"(%"PRId64")", entry->user_id, entry->group_id);
83  if (cnt == 0)
84  av_log(NULL, AV_LOG_INFO, "%-9s %12s %30s %10s %s %16s %16s %16s\n",
85  "TYPE", "SIZE", "NAME", "UID(GID)", "UGO", "MODIFIED",
86  "ACCESSED", "STATUS_CHANGED");
87  av_log(NULL, AV_LOG_INFO, "%-9s %12"PRId64" %30s %10s %s %16"PRId64" %16"PRId64" %16"PRId64"\n",
88  type_string(entry->type),
89  entry->size,
90  entry->name,
91  uid_and_gid,
92  filemode,
94  entry->access_timestamp,
97  cnt++;
98  };
99 
100  fail:
102  return ret;
103 }
104 
105 static void usage(const char *program_name)
106 {
107  fprintf(stderr, "usage: %s input_dir\n"
108  "API example program to show how to list files in directory "
109  "accessed through AVIOContext.\n", program_name);
110 }
111 
112 int main(int argc, char *argv[])
113 {
114  int ret;
115 
117 
118  if (argc < 2) {
119  usage(argv[0]);
120  return 1;
121  }
122 
124 
125  ret = list_op(argv[1]);
126 
128 
129  return ret < 0 ? 1 : 0;
130 }
usage
static void usage(const char *program_name)
Definition: avio_list_dir.c:105
error
static void error(const char *err)
Definition: target_bsf_fuzzer.c:31
M
#define M(a, b)
Definition: vp3dsp.c:48
generate
static av_always_inline void generate(int8_t *out, int out_stride, const uint8_t *in, int in_stride, H274FilmGrainDatabase *database, const AVFilmGrainH274Params *h274, int c, int invert, int deblock, int y_offset, int x_offset)
Definition: h274.c:156
be
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it be(in the first position) for now. Options ------- Then comes the options array. This is what will define the user accessible options. For example
Channel
Definition: aptx.h:83
process
static void process(NormalizeContext *s, AVFrame *in, AVFrame *out)
Definition: vf_normalize.c:156
name
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option name
Definition: writing_filters.txt:88
program
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C program
Definition: undefined.txt:6
errors
FFmpeg currently uses a custom build this text attempts to document some of its obscure features and options Makefile the full command issued by make and its output will be shown on the screen DBG Preprocess x86 external assembler files to a dbg asm file in the object which then gets compiled Helps in developing those assembler files DESTDIR Destination directory for the install useful to prepare packages or install FFmpeg in cross environments GEN Set to ‘1’ to generate the missing or mismatched references Makefile builds all the libraries and the executables fate Run the fate test note that you must have installed it fate list List all fate regression test targets install Install libraries and programs examples Build all examples located in doc examples checkheaders Check headers dependencies alltools Build all tools in tools directory config Reconfigure the project with the current configuration tools target_dec_< decoder > _fuzzer Build fuzzer to fuzz the specified decoder tools target_bsf_< filter > _fuzzer Build fuzzer to fuzz the specified bitstream filter Useful standard make this is useful to reduce unneeded rebuilding when changing but note that you must force rebuilds of files that actually need it by hand then make j< num > Rebuild with multiple jobs at the same time Faster on multi processor systems make k Continue build in case of errors
Definition: build_system.txt:64
space
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated space
Definition: undefined.txt:4
out
FILE * out
Definition: movenc.c:54
is
The official guide to swscale for confused that is
Definition: swscale.txt:28
message
Definition: api-threadmessage-test.c:46
exchange
static int exchange(MqcState *mqc, uint8_t *cxstate, int lps)
Definition: mqcdec.c:45
output
filter_frame For filters that do not use the this method is called when a frame is pushed to the filter s input It can be called at any time except in a reentrant way If the input frame is enough to produce output
Definition: filter_design.txt:225
program_name
const char program_name[]
program name, defined by the program for show_version().
Definition: ffmpeg.c:109
w
uint8_t w
Definition: llviddspenc.c:38
AVIODirEntry::type
int type
Type of the entry.
Definition: avio.h:88
targets
FFmpeg currently uses a custom build this text attempts to document some of its obscure features and options Makefile the full command issued by make and its output will be shown on the screen DBG Preprocess x86 external assembler files to a dbg asm file in the object which then gets compiled Helps in developing those assembler files DESTDIR Destination directory for the install targets
Definition: build_system.txt:16
b
#define b
Definition: input.c:40
W
@ W
Definition: vf_addroi.c:26
table
static const uint16_t table[]
Definition: prosumer.c:206
AVIO_ENTRY_NAMED_PIPE
@ AVIO_ENTRY_NAMED_PIPE
Definition: avio.h:71
data
const char data[16]
Definition: mxf.c:143
possible
the frame and frame reference mechanism is intended to as much as possible
Definition: filter_design.txt:45
F
#define F(x)
filter
filter_frame For filters that do not use the this method is called when a frame is pushed to the filter s input It can be called at any time except in a reentrant way If the input frame is enough to produce then the filter should push the output frames on the output link immediately As an exception to the previous rule if the input frame is enough to produce several output frames then the filter needs output only at least one per link The additional frames can be left buffered in the filter
Definition: filter_design.txt:228
AVIO_ENTRY_UNKNOWN
@ AVIO_ENTRY_UNKNOWN
Definition: avio.h:67
AVIODirEntry::access_timestamp
int64_t access_timestamp
Time of last access in microseconds since unix epoch, -1 if unknown.
Definition: avio.h:94
some
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that some(invalid) inputs can trigger overflows(undefined behavior). In these cases
decoder
static const chunk_decoder decoder[8]
Definition: dfa.c:330
AVIO_ENTRY_DIRECTORY
@ AVIO_ENTRY_DIRECTORY
Definition: avio.h:70
fail
#define fail()
Definition: checkasm.h:127
AVIO_ENTRY_CHARACTER_DEVICE
@ AVIO_ENTRY_CHARACTER_DEVICE
Definition: avio.h:69
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
ss
#define ss(width, name, subs,...)
Definition: cbs_vp9.c:261
avformat_network_init
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:1252
X
@ X
Definition: vf_addroi.c:26
avio_free_directory_entry
void avio_free_directory_entry(AVIODirEntry **entry)
Free entry allocated by avio_read_dir().
Definition: avio.c:597
AVIODirEntry::modification_timestamp
int64_t modification_timestamp
Time of last modification in microseconds since unix epoch, -1 if unknown.
Definition: avio.h:92
variables
FFmpeg currently uses a custom build this text attempts to document some of its obscure features and options Makefile variables
Definition: build_system.txt:7
list_op
static int list_op(const char *input_dir)
Definition: avio_list_dir.c:57
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
AVIO_ENTRY_SYMBOLIC_LINK
@ AVIO_ENTRY_SYMBOLIC_LINK
Definition: avio.h:72
to
const char * to
Definition: webvttdec.c:35
avio_close_dir
int avio_close_dir(AVIODirContext **s)
Close directory.
Definition: avio.c:582
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
ctx
AVFormatContext * ctx
Definition: movenc.c:48
on
s EdgeDetect Foobar g libavfilter vf_edgedetect c libavfilter vf_foobar c edit libavfilter and add an entry for foobar following the pattern of the other filters edit libavfilter allfilters and add an entry for foobar following the pattern of the other filters configure make j< whatever > ffmpeg ffmpeg i you should get a foobar png with Lena edge detected That s your new playground is ready Some little details about what s going on
Definition: writing_filters.txt:34
key
const char * key
Definition: hwcontext_opencl.c:168
command
static int command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
Definition: vf_drawtext.c:906
link
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 link
Definition: filter_design.txt:23
need
must be printed separately If there s no standard function for printing the type you need
Definition: tablegen.txt:45
main
int main(int argc, char *argv[])
Definition: avio_list_dir.c:112
NULL
#define NULL
Definition: coverity.c:32
run
uint8_t run
Definition: svq3.c:203
AVIODirEntry::size
int64_t size
File size in bytes, -1 if unknown.
Definition: avio.h:91
state
static struct @317 state
system
FFmpeg currently uses a custom build system
Definition: build_system.txt:1
AVIODirEntry::name
char * name
Filename.
Definition: avio.h:87
V
#define V
Definition: avdct.c:30
list
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 list
Definition: filter_design.txt:25
not
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 not
Definition: filter_design.txt:259
AVIO_ENTRY_FILE
@ AVIO_ENTRY_FILE
Definition: avio.h:74
commands
FFmpeg currently uses a custom build this text attempts to document some of its obscure features and options Makefile the full command issued by make and its output will be shown on the screen DBG Preprocess x86 external assembler files to a dbg asm file in the object which then gets compiled Helps in developing those assembler files DESTDIR Destination directory for the install useful to prepare packages or install FFmpeg in cross environments GEN Set to ‘1’ to generate the missing or mismatched references Makefile builds all the libraries and the executables fate Run the fate test note that you must have installed it fate list List all fate regression test targets install Install libraries and programs examples Build all examples located in doc examples checkheaders Check headers dependencies alltools Build all tools in tools directory config Reconfigure the project with the current configuration tools target_dec_< decoder > _fuzzer Build fuzzer to fuzz the specified decoder tools target_bsf_< filter > _fuzzer Build fuzzer to fuzz the specified bitstream filter Useful standard make commands
Definition: build_system.txt:56
AVIODirEntry::group_id
int64_t group_id
Group ID of owner, -1 if unknown.
Definition: avio.h:99
avio_read_dir
int avio_read_dir(AVIODirContext *s, AVIODirEntry **next)
Get next directory entry.
Definition: avio.c:569
AVIODirEntry::filemode
int64_t filemode
Unix file mode, -1 if unknown.
Definition: avio.h:100
for
for(j=16;j >0;--j)
Definition: h264pred_template.c:469
suite
FFmpeg currently uses a custom build this text attempts to document some of its obscure features and options Makefile the full command issued by make and its output will be shown on the screen DBG Preprocess x86 external assembler files to a dbg asm file in the object which then gets compiled Helps in developing those assembler files DESTDIR Destination directory for the install useful to prepare packages or install FFmpeg in cross environments GEN Set to ‘1’ to generate the missing or mismatched references Makefile builds all the libraries and the executables fate Run the fate test suite
Definition: build_system.txt:28
Block
Definition: flashsv2enc.c:69
options
const OptionDef options[]
byte
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_WB16 unsigned int_TMPL byte
Definition: bytestream.h:99
av_err2str
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:121
Program
Definition: mpegts.c:117
AVIODirEntry
Describes single entry of the directory.
Definition: avio.h:86
avio.h
section
Definition: ffprobe.c:147
a
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:41
AVIODirEntry::status_change_timestamp
int64_t status_change_timestamp
Time of last status change in microseconds since unix epoch, -1 if unknown.
Definition: avio.h:96
that
if it could not because there are no more it should return AVERROR_EOF The typical implementation of request_frame for a filter with several inputs will look like that
Definition: filter_design.txt:273
version
version
Definition: libkvazaar.c:307
AVIO_ENTRY_SOCKET
@ AVIO_ENTRY_SOCKET
Definition: avio.h:73
AV_LOG_INFO
#define AV_LOG_INFO
Standard information.
Definition: log.h:191
assign
#define assign(var, type, n)
AVIODirEntry::user_id
int64_t user_id
User ID of owner, -1 if unknown.
Definition: avio.h:98
tests
const TestCase tests[]
Definition: fifo_muxer.c:242
av_log_set_level
void av_log_set_level(int level)
Set the log level.
Definition: log.c:440
code
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
Definition: filter_design.txt:178
available
if no frame is available
Definition: filter_design.txt:166
Code
One code in hash table.
Definition: lzwenc.c:43
needed
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is needed
Definition: filter_design.txt:212
avio_open_dir
int avio_open_dir(AVIODirContext **s, const char *url, AVDictionary **options)
Open directory for reading.
Definition: avio.c:531
avcodec.h
AVIO_ENTRY_BLOCK_DEVICE
@ AVIO_ENTRY_BLOCK_DEVICE
Definition: avio.h:68
directory
FFmpeg currently uses a custom build this text attempts to document some of its obscure features and options Makefile the full command issued by make and its output will be shown on the screen DBG Preprocess x86 external assembler files to a dbg asm file in the object directory
Definition: build_system.txt:12
files
Writing a table generator This documentation is preliminary Parts of the API are not good and should be changed Basic concepts A table generator consists of two files
Definition: tablegen.txt:8
ret
ret
Definition: filter_design.txt:187
currently
The official guide to swscale for confused that consecutive non overlapping rectangles of slice_bottom special converter These generally are unscaled converters of common like for each output line the vertical scaler pulls lines from a ring buffer When the ring buffer does not contain the wanted then it is pulled from the input slice through the input converter and horizontal scaler The result is also stored in the ring buffer to serve future vertical scaler requests When no more output can be generated because lines from a future slice would be then all remaining lines in the current slice are horizontally scaled and put in the ring buffer[This is done for luma and chroma, each with possibly different numbers of lines per picture.] Input to YUV Converter When the input to the main path is not planar bits per component YUV or bit it is converted to planar bit YUV Two sets of converters exist for this currently
Definition: swscale.txt:54
links
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 links
Definition: filter_design.txt:14
AVIODirContext
Definition: avio.h:103
type_string
static const char * type_string(int type)
Definition: avio_list_dir.c:27
avformat.h
left
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2] ... the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so ...,+,-,+,-,+,+,-,+,-,+,... hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32 - hcoeff[1] - hcoeff[2] - ... a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2} an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||......... intra?||||:Block01 :yes no||||:Block02 :....... ..........||||:Block03 ::y DC ::ref index:||||:Block04 ::cb DC ::motion x :||||......... :cr DC ::motion y :||||....... ..........|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------ ------------ ------------|||Y subbands||Cb subbands||Cr subbands||||--- ---||--- ---||--- ---|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------ ------------ ------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction ------------|\ Dequantization ------------------- \||Reference frames|\ IDWT|------- -------|Motion \|||Frame 0||Frame 1||Compensation . OBMC v -------|------- -------|--------------. \------> Frame n output Frame Frame<----------------------------------/|...|------------------- Range Coder:============Binary Range Coder:------------------- The implemented range coder is an adapted version based upon "Range encoding: an algorithm for removing redundancy from a digitised message." by G. N. N. Martin. The symbols encoded by the Snow range coder are bits(0|1). The associated probabilities are not fix but change depending on the symbol mix seen so far. bit seen|new state ---------+----------------------------------------------- 0|256 - state_transition_table[256 - old_state];1|state_transition_table[old_state];state_transition_table={ 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:------------------------- FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1. the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled left
Definition: snow.txt:386
L
#define L(x)
Definition: vp56_arith.h:36
avformat_network_deinit
int avformat_network_deinit(void)
Undo the initialization done by avformat_network_init.
Definition: utils.c:1264
B
#define B
Definition: huffyuvdsp.h:32
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
mode
mode
Definition: ebur128.h:83
headers
FFmpeg currently uses a custom build this text attempts to document some of its obscure features and options Makefile the full command issued by make and its output will be shown on the screen DBG Preprocess x86 external assembler files to a dbg asm file in the object which then gets compiled Helps in developing those assembler files DESTDIR Destination directory for the install useful to prepare packages or install FFmpeg in cross environments GEN Set to ‘1’ to generate the missing or mismatched references Makefile builds all the libraries and the executables fate Run the fate test note that you must have installed it fate list List all fate regression test targets install Install headers
Definition: build_system.txt:34
test
static void test(const char *pattern, const char *host)
Definition: noproxy.c:23
note
F H1 F F H1 F F F F H1<-F-------F-------F v v v H2 H3 H2 ^ ^ ^ F-------F-------F-> H1<-F-------F-------F|||||||||F H1 F|||||||||F H1 Funavailable fullpel samples(outside the picture for example) shall be equalto the closest available fullpel sampleSmaller pel interpolation:--------------------------if diag_mc is set then points which lie on a line between 2 vertically, horizontally or diagonally adjacent halfpel points shall be interpolatedlinearly with rounding to nearest and halfway values rounded up.points which lie on 2 diagonals at the same time should only use the onediagonal not containing the fullpel point F--> O q O<--h1-> O q O<--F v \/v \/v O O O O O O O|/|\|q q q q q|/|\|O O O O O O O ^/\ ^/\ ^ h2--> O q O<--h3-> O q O<--h2 v \/v \/v O O O O O O O|\|/|q q q q q|\|/|O O O O O O O ^/\ ^/\ ^ F--> O q O<--h1-> O q O<--Fthe remaining points shall be bilinearly interpolated from theup to 4 surrounding halfpel and fullpel points, again rounding should be tonearest and halfway values rounded upcompliant Snow decoders MUST support 1-1/8 pel luma and 1/2-1/16 pel chromainterpolation at leastOverlapped block motion compensation:-------------------------------------FIXMELL band prediction:===================Each sample in the LL0 subband is predicted by the median of the left, top andleft+top-topleft samples, samples outside the subband shall be considered tobe 0. To reverse this prediction in the decoder apply the following.for(y=0;y< height;y++){ for(x=0;x< width;x++){ sample[y][x]+=median(sample[y-1][x], sample[y][x-1], sample[y-1][x]+sample[y][x-1]-sample[y-1][x-1]);}}sample[-1][ *]=sample[ *][-1]=0;width, height here are the width and height of the LL0 subband not of the finalvideoDequantization:===============FIXMEWavelet Transform:==================Snow supports 2 wavelet transforms, the symmetric biorthogonal 5/3 integertransform and an integer approximation of the symmetric biorthogonal 9/7daubechies wavelet.2D IDWT(inverse discrete wavelet transform) --------------------------------------------The 2D IDWT applies a 2D filter recursively, each time combining the4 lowest frequency subbands into a single subband until only 1 subbandremains.The 2D filter is done by first applying a 1D filter in the vertical directionand then applying it in the horizontal one. --------------- --------------- --------------- ---------------|LL0|HL0|||||||||||||---+---|HL1||L0|H0|HL1||LL1|HL1|||||LH0|HH0|||||||||||||-------+-------|-> L1 H1 LH1 HH1 LH1 HH1 LH1 HH1 note
Definition: snow.txt:555
AVIO_ENTRY_WORKGROUP
@ AVIO_ENTRY_WORKGROUP
Definition: avio.h:77
bad
static int bad(InterplayACMContext *s, unsigned ind, unsigned col)
Definition: interplayacm.c:126
it
s EdgeDetect Foobar g libavfilter vf_edgedetect c libavfilter vf_foobar c edit libavfilter and add an entry for foobar following the pattern of the other filters edit libavfilter allfilters and add an entry for foobar following the pattern of the other filters configure make j< whatever > ffmpeg ffmpeg i you should get a foobar png with Lena edge detected That s it
Definition: writing_filters.txt:31
format
fg outputs[0] format
Definition: ffmpeg_filter.c:175
AVIO_ENTRY_SERVER
@ AVIO_ENTRY_SERVER
Definition: avio.h:75
Stream
Definition: mpegts.c:110
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
project
static float project(float origin_x, float origin_y, float dest_x, float dest_y, int point_x, int point_y)
Definition: vsrc_gradients.c:153
snprintf
#define snprintf
Definition: snprintf.h:34
AVIO_ENTRY_SHARE
@ AVIO_ENTRY_SHARE
Definition: avio.h:76