FFmpeg: libavformat/teeproto.c Source File

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libavformat

teeproto.c

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1 /*

2 * Tee output protocol

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 */

22 #include "libavutil/avstring.h"

23 #include "libavutil/opt.h"

24 #include "avformat.h"

25 #include "avio_internal.h"

26 #include "tee_common.h"

28 typedef struct ChildContext {

29 URLContext *url_context;

30 } ChildContext;

32 typedef struct TeeContext {

33 const AVClass *class;

34 int child_count;

35 ChildContext *child;

36 } TeeContext;

38 static const AVOption tee_options[] = {

39 { NULL }

40 };

42 static const AVClass tee_class = {

43 .class_name = "tee",

44 .item_name = av_default_item_name,

45 .option = tee_options,

46 .version = LIBAVUTIL_VERSION_INT,

47 };

49 static const char *const child_delim = "|";

51 static int tee_write(URLContext *h, const unsigned char *buf, int size)

52 {

53 TeeContext *c = h->priv_data;

54 int i;

55 int main_ret = size;

57 for (i=0; i<c->child_count; i++) {

58 int ret = ffurl_write(c->child[i].url_context, buf, size);

59 if (ret < 0)

60 main_ret = ret;

61 }

62 return main_ret;

63 }

65 static int tee_close(URLContext *h)

66 {

67 TeeContext *c = h->priv_data;

68 int i;

69 int main_ret = 0;

71 for (i=0; i<c->child_count; i++) {

72 int ret = ffurl_closep(&c->child[i].url_context);

73 if (ret < 0)

74 main_ret = ret;

75 }

77 av_freep(&c->child);

78 c->child_count = 0;

79 return main_ret;

80 }

82 static int tee_open(URLContext *h, const char *filename, int flags)

83 {

84 TeeContext *c = h->priv_data;

85 int ret, i;

87 av_strstart(filename, "tee:", &filename);

89 if (flags & AVIO_FLAG_READ)

90 return AVERROR(ENOSYS);

92 while (*filename) {

93 char *child_string = av_get_token(&filename, child_delim);

94 char *child_name = NULL;

95 void *tmp;

96 AVDictionary *options = NULL;

97 if (!child_string) {

98 ret = AVERROR(ENOMEM);

99 goto fail;

100 }

101

102 tmp = av_realloc_array(c->child, c->child_count + 1, sizeof(*c->child));

103 if (!tmp) {

104 ret = AVERROR(ENOMEM);

105 goto loop_fail;

106 }

107 c->child = tmp;

108 memset(&c->child[c->child_count], 0, sizeof(c->child[c->child_count]));

109

110 ret = ff_tee_parse_slave_options(h, child_string, &options, &child_name);

111 if (ret < 0)

112 goto loop_fail;

113

114 ret = ffurl_open_whitelist(&c->child[c->child_count].url_context, child_name, flags,

115 &h->interrupt_callback, &options,

116 h->protocol_whitelist, h->protocol_blacklist,

117 h);

118 loop_fail:

119 av_freep(&child_string);

120 av_dict_free(&options);

121 if (ret < 0)

122 goto fail;

123 c->child_count++;

124

125 if (strspn(filename, child_delim))

126 filename++;

127 }

128

129 h->is_streamed = 0;

130 for (i=0; i<c->child_count; i++) {

131 h->is_streamed |= c->child[i].url_context->is_streamed;

132 }

133

134 return 0;

135 fail:

136 tee_close(h);

137 return ret;

138 }

139 const URLProtocol ff_tee_protocol = {

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 .priv_data_class = &tee_class,

146 .default_whitelist = "crypto,file,http,https,httpproxy,rtmp,tcp,tls"

147 };

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

opt.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:154

tee_write

static int tee_write(URLContext *h, const unsigned char *buf, int size)

Definition: teeproto.c:51

ff_tee_protocol

const URLProtocol ff_tee_protocol

Definition: teeproto.c:139

ChildContext::url_context

URLContext * url_context

Definition: teeproto.c:29

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

AVOption

AVOption.

Definition: opt.h:251

AVDictionary

Definition: dict.c:30

TeeContext::child_count

int child_count

Definition: teeproto.c:34

URLProtocol

Definition: url.h:53

tee_common.h

fail

#define fail()

Definition: checkasm.h:131

tee_close

static int tee_close(URLContext *h)

Definition: teeproto.c:65

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:306

tee_options

static const AVOption tee_options[]

Definition: teeproto.c:38

av_realloc_array

void * av_realloc_array(void *ptr, size_t nmemb, size_t size)

Definition: mem.c:225

LIBAVUTIL_VERSION_INT

#define LIBAVUTIL_VERSION_INT

Definition: version.h:85

AVClass

Describe the class of an AVClass context structure.

Definition: log.h:66

NULL

#define NULL

Definition: coverity.c:32

av_default_item_name

const char * av_default_item_name(void *ptr)

Return the context name.

Definition: log.c:237

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

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:28

TeeContext