/*
* Copyright (c) 2011 Reinhard Tartler
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#pragma
comment
(
lib
,
"avformat.lib"
)
#pragma
comment
(
lib
,
"avcodec.lib"
)
#pragma
comment
(
lib
,
"avdevice.lib"
)
#pragma
comment
(
lib
,
"avfilter.lib"
)
#pragma
comment
(
lib
,
"avutil.lib"
)
#pragma
comment
(
lib
,
"postproc.lib"
)
#pragma
comment
(
lib
,
"swresample.lib"
)
#pragma
comment
(
lib
,
"swscale.lib"
)
/**
* @file
* libavformat AVIOContext API example.
*
* Make libavformat demuxer access media content through a custom
* AVIOContext read callback.
* @example avio_reading.c
*/
extern
"C"
{
#include
<libavcodec/avcodec.h>
#include
<libavformat/avformat.h>
#include
<libavformat/avio.h>
#include
<libavutil/file.h>
}
struct
buffer_data
{
uint8_t
*
ptr
;
size_t
size
;
///< size left in the buffer
};
static
int
read_packet
(
void
*
opaque
,
uint8_t
*
buf
,
int
buf_size
)
{
struct
buffer_data
*
bd
= (
struct
buffer_data
*)
opaque
;
buf_size
=
FFMIN
(
buf_size
,
bd
->
size
);
printf
(
"ptr:%p size:%zu\n"
,
bd
->
ptr
,
bd
->
size
);
/* copy internal buffer data to buf */
memcpy
(
buf
,
bd
->
ptr
,
buf_size
);
bd
->
ptr
+=
buf_size
;
bd
->
size
-=
buf_size
;
return
buf_size
;
}
int
main
(
int
argc
,
char
*
argv
[])
{
AVFormatContext
*
fmt_ctx
=
NULL
;
AVIOContext
*
avio_ctx
=
NULL
;
uint8_t
*
buffer
=
NULL
, *
avio_ctx_buffer
=
NULL
;
size_t
buffer_size
,
avio_ctx_buffer_size
= 4096;
char
*
input_filename
=
"E:/video_source/1.mp4"
;
int
ret
= 0;
struct
buffer_data
bd
= { 0 };
/*
if (argc != 2) {
fprintf(stderr, "usage: %s input_file\n"
"API example program to show how to read from a custom buffer "
"accessed through AVIOContext.\n", argv[0]);
return 1;
}*/
/* register codecs and formats and other lavf/lavc components*/
av_register_all
();
/* slurp file content into buffer */
ret
=
av_file_map
(
input_filename
, &
buffer
, &
buffer_size
, 0,
NULL
);
if
(
ret
< 0)
goto
end
;
/* fill opaque structure used by the AVIOContext read callback */
bd
.
ptr
=
buffer
;
bd
.
size
=
buffer_size
;
if
(!(
fmt_ctx
=
avformat_alloc_context
())) {
ret
=
AVERROR
(
ENOMEM
);
goto
end
;
}
avio_ctx_buffer
= (
uint8_t
*)av_malloc(
avio_ctx_buffer_size
);
if
(!
avio_ctx_buffer
) {
ret
=
AVERROR
(
ENOMEM
);
goto
end
;
}
avio_ctx
=
avio_alloc_context
(
avio_ctx_buffer
,
avio_ctx_buffer_size
,
0, &
bd
, &
read_packet
,
NULL
,
NULL
);
if
(!
avio_ctx
) {
ret
=
AVERROR
(
ENOMEM
);
goto
end
;
}
fmt_ctx
->
pb
=
avio_ctx
;
ret
=
avformat_open_input
(&
fmt_ctx
,
NULL
,
NULL
,
NULL
);
if
(
ret
< 0) {
fprintf
(
stderr
,
"Could not open input\n"
);
goto
end
;
}
ret
=
avformat_find_stream_info
(
fmt_ctx
,
NULL
);
if
(
ret
< 0) {
fprintf
(
stderr
,
"Could not find stream information\n"
);
goto
end
;
}
av_dump_format
(
fmt_ctx
, 0,
input_filename
, 0);
end
:
avformat_close_input
(&
fmt_ctx
);
/* note: the internal buffer could have changed, and be != avio_ctx_buffer */
if
(
avio_ctx
) {
av_freep
(&
avio_ctx
->
buffer
);
av_freep
(&
avio_ctx
);
}
av_file_unmap
(
buffer
,
buffer_size
);
if
(
ret
< 0) {
fprintf
(
stderr
,
"Error occurred: %s\n"
,
av_err2str
(
ret
));
return
1;
}
while
(
true
)
{
}
return
0;
}
运行结果：
