FFmpeg
teeproto.c
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1 /*
2  * Tee output protocol
3  * Copyright (c) 2016 Michael Niedermayer
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 
22 #include <string.h>
23 
24 #include "libavutil/avstring.h"
25 #include "libavutil/dict.h"
26 #include "libavutil/error.h"
27 #include "libavutil/mem.h"
28 #include "tee_common.h"
29 #include "url.h"
30 
31 typedef struct ChildContext {
33 } ChildContext;
34 
35 typedef struct TeeContext {
38 } TeeContext;
39 
40 static const char *const child_delim = "|";
41 
42 static int tee_write(URLContext *h, const unsigned char *buf, int size)
43 {
44  TeeContext *c = h->priv_data;
45  int i;
46  int main_ret = size;
47 
48  for (i=0; i<c->child_count; i++) {
49  int ret = ffurl_write(c->child[i].url_context, buf, size);
50  if (ret < 0)
51  main_ret = ret;
52  }
53  return main_ret;
54 }
55 
56 static int tee_close(URLContext *h)
57 {
58  TeeContext *c = h->priv_data;
59  int i;
60  int main_ret = 0;
61 
62  for (i=0; i<c->child_count; i++) {
63  int ret = ffurl_closep(&c->child[i].url_context);
64  if (ret < 0)
65  main_ret = ret;
66  }
67 
68  av_freep(&c->child);
69  c->child_count = 0;
70  return main_ret;
71 }
72 
73 static int tee_open(URLContext *h, const char *filename, int flags)
74 {
75  TeeContext *c = h->priv_data;
76  int ret, i;
77 
78  av_strstart(filename, "tee:", &filename);
79 
80  while (*filename) {
81  char *child_string = av_get_token(&filename, child_delim);
82  char *child_name = NULL;
83  void *tmp;
85  if (!child_string) {
86  ret = AVERROR(ENOMEM);
87  goto fail;
88  }
89 
90  tmp = av_realloc_array(c->child, c->child_count + 1, sizeof(*c->child));
91  if (!tmp) {
92  ret = AVERROR(ENOMEM);
93  goto loop_fail;
94  }
95  c->child = tmp;
96  memset(&c->child[c->child_count], 0, sizeof(c->child[c->child_count]));
97 
98  ret = ff_tee_parse_slave_options(h, child_string, &options, &child_name);
99  if (ret < 0)
100  goto loop_fail;
101 
102  ret = ffurl_open_whitelist(&c->child[c->child_count].url_context, child_name, flags,
103  &h->interrupt_callback, &options,
104  h->protocol_whitelist, h->protocol_blacklist,
105  h);
106 loop_fail:
107  av_freep(&child_string);
109  if (ret < 0)
110  goto fail;
111  c->child_count++;
112 
113  if (strspn(filename, child_delim))
114  filename++;
115  }
116 
117  h->is_streamed = 0;
118  for (i=0; i<c->child_count; i++) {
119  h->is_streamed |= c->child[i].url_context->is_streamed;
120  }
121 
122  h->max_packet_size = 0;
123  for (i = 0; i < c->child_count; i++) {
124  int max = c->child[i].url_context->max_packet_size;
125  if (!max)
126  continue;
127 
128  if (!h->max_packet_size)
129  h->max_packet_size = max;
130  else if (h->max_packet_size > max)
131  h->max_packet_size = max;
132  }
133 
134  return 0;
135 fail:
136  tee_close(h);
137  return ret;
138 }
140  .name = "tee",
141  .url_open = tee_open,
142  .url_write = tee_write,
143  .url_close = tee_close,
144  .priv_data_size = sizeof(TeeContext),
145  .default_whitelist = "crypto,file,http,https,httpproxy,rtmp,tcp,tls"
146 };
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
tee_write
static int tee_write(URLContext *h, const unsigned char *buf, int size)
Definition: teeproto.c:42
ff_tee_protocol
const URLProtocol ff_tee_protocol
Definition: teeproto.c:139
ffurl_write
static int ffurl_write(URLContext *h, const uint8_t *buf, int size)
Write size bytes from buf to the resource accessed by h.
Definition: url.h:208
ChildContext::url_context
URLContext * url_context
Definition: teeproto.c:32
tmp
static uint8_t tmp[11]
Definition: aes_ctr.c:28
ff_tee_parse_slave_options
int ff_tee_parse_slave_options(void *log, char *slave, AVDictionary **options, char **filename)
Definition: tee_common.c:33
max
#define max(a, b)
Definition: cuda_runtime.h:33
AVDictionary
Definition: dict.c:34
TeeContext::child_count
int child_count
Definition: teeproto.c:36
URLProtocol
Definition: url.h:53
tee_common.h
fail
#define fail()
Definition: checkasm.h:179
tee_close
static int tee_close(URLContext *h)
Definition: teeproto.c:56
ffurl_open_whitelist
int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options, const char *whitelist, const char *blacklist, URLContext *parent)
Create an URLContext for accessing to the resource indicated by url, and open it.
Definition: avio.c:300
av_realloc_array
void * av_realloc_array(void *ptr, size_t nmemb, size_t size)
Definition: mem.c:215
NULL
#define NULL
Definition: coverity.c:32
c
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 often the output of the computation does not c
Definition: undefined.txt:32
error.h
options
const OptionDef options[]
size
int size
Definition: twinvq_data.h:10344
URLProtocol::name
const char * name
Definition: url.h:54
ChildContext
Definition: teeproto.c:31
TeeContext
Definition: tee.c:53
av_dict_free
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values.
Definition: dict.c:225
av_strstart
int av_strstart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str.
Definition: avstring.c:36
child_delim
static const char *const child_delim
Definition: teeproto.c:40
URLContext
Definition: url.h:37
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:255
TeeContext::child
ChildContext * child
Definition: teeproto.c:37
tee_open
static int tee_open(URLContext *h, const char *filename, int flags)
Definition: teeproto.c:73
url.h
ffurl_closep
int ffurl_closep(URLContext **hh)
Close the resource accessed by the URLContext h, and free the memory used by it.
Definition: avio.c:439
ret
ret
Definition: filter_design.txt:187
dict.h
av_get_token
char * av_get_token(const char **buf, const char *term)
Unescape the given string until a non escaped terminating char, and return the token corresponding to...
Definition: avstring.c:143
mem.h
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
h
h
Definition: vp9dsp_template.c:2038
avstring.h