FFmpeg
ccfifo.h
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1 /*
2  * CEA-708 Closed Captioning FIFO
3  * Copyright (c) 2023 LTN Global Communications
4  *
5  * Author: Devin Heitmueller <dheitmueller@ltnglobal.com>
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 /**
25  * @file
26  * CC FIFO Buffer
27  */
28 
29 #ifndef AVFILTER_CCFIFO_H
30 #define AVFILTER_CCFIFO_H
31 
32 #include <stddef.h>
33 #include <stdint.h>
34 
35 #include "libavutil/frame.h"
36 #include "libavutil/rational.h"
37 
38 #define CC_BYTES_PER_ENTRY 3
39 
40 typedef struct CCFifo {
49  void *log_ctx;
50 } CCFifo;
51 
52 /**
53  * Initialize a CCFifo.
54  *
55  * @param framerate output framerate
56  * @param log_ctx used for any av_log() calls
57  * @return Zero on success, or negative AVERROR code on failure.
58  */
59 int ff_ccfifo_init(CCFifo *ccf, AVRational framerate, void *log_ctx);
60 
61 /**
62  * Free all memory allocated in a CCFifo and clear the context.
63  *
64  * @param ccf Pointer to the CCFifo which should be uninitialized
65  */
66 void ff_ccfifo_uninit(CCFifo *ccf);
67 
68 /**
69  * Extract CC data from an AVFrame
70  *
71  * Extract CC bytes from the AVFrame, insert them into our queue, and
72  * remove the side data from the AVFrame. The side data is removed
73  * as it will be re-inserted at the appropriate rate later in the
74  * filter.
75  *
76  * @param af CCFifo to write to
77  * @param frame AVFrame with the video frame to operate on
78  * @return Zero on success, or negative AVERROR
79  * code on failure.
80  */
82 
83 /**
84  *Just like ff_ccfifo_extract(), but takes the raw bytes instead of an AVFrame
85  */
86 int ff_ccfifo_extractbytes(CCFifo *ccf, uint8_t *data, size_t len);
87 
88 /**
89  * Provide the size in bytes of an output buffer to allocate
90  *
91  * Ask for how many bytes the output will contain, so the caller can allocate
92  * an appropriately sized buffer and pass it to ff_ccfifo_injectbytes()
93  *
94  */
95 static inline int ff_ccfifo_getoutputsize(const CCFifo *ccf)
96 {
98 }
99 
100 
101 /**
102  * Insert CC data from the FIFO into an AVFrame (as side data)
103  *
104  * Dequeue the appropriate number of CC tuples based on the
105  * frame rate, and insert them into the AVFrame
106  *
107  * @param af CCFifo to read from
108  * @param frame AVFrame with the video frame to operate on
109  * @return Zero on success, or negative AVERROR
110  * code on failure.
111  */
113 
114 /**
115  * Just like ff_ccfifo_inject(), but takes the raw bytes to insert the CC data
116  * int rather than an AVFrame
117  */
118 int ff_ccfifo_injectbytes(CCFifo *ccf, uint8_t *data, size_t len);
119 
120 /**
121  * Returns 1 if captions have been found as a prior call
122  * to ff_ccfifo_extract() or ff_ccfifo_extractbytes()
123  */
124 static inline int ff_ccfifo_ccdetected(const CCFifo *ccf)
125 {
126  return ccf->cc_detected;
127 }
128 
129 #endif /* AVFILTER_CCFIFO_H */
rational.h
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
CCFifo::framerate
AVRational framerate
Definition: ccfifo.h:43
data
const char data[16]
Definition: mxf.c:148
ff_ccfifo_uninit
void ff_ccfifo_uninit(CCFifo *ccf)
Free all memory allocated in a CCFifo and clear the context.
Definition: ccfifo.c:46
ff_ccfifo_inject
int ff_ccfifo_inject(CCFifo *ccf, AVFrame *frame)
Insert CC data from the FIFO into an AVFrame (as side data)
Definition: ccfifo.c:133
CCFifo::expected_608
int expected_608
Definition: ccfifo.h:45
CCFifo::cc_detected
int cc_detected
Definition: ccfifo.h:46
ff_ccfifo_injectbytes
int ff_ccfifo_injectbytes(CCFifo *ccf, uint8_t *data, size_t len)
Just like ff_ccfifo_inject(), but takes the raw bytes to insert the CC data int rather than an AVFram...
Definition: ccfifo.c:92
ff_ccfifo_getoutputsize
static int ff_ccfifo_getoutputsize(const CCFifo *ccf)
Provide the size in bytes of an output buffer to allocate.
Definition: ccfifo.h:95
frame
static AVFrame * frame
Definition: demux_decode.c:54
CCFifo::passthrough
int passthrough
Definition: ccfifo.h:47
framerate
float framerate
Definition: av1_levels.c:29
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
CCFifo::cc_608_fifo
struct AVFifo * cc_608_fifo
Definition: ccfifo.h:41
CCFifo
Definition: ccfifo.h:40
AVFifo
Definition: fifo.c:35
CC_BYTES_PER_ENTRY
#define CC_BYTES_PER_ENTRY
Definition: ccfifo.h:38
frame.h
ff_ccfifo_extractbytes
int ff_ccfifo_extractbytes(CCFifo *ccf, uint8_t *data, size_t len)
Just like ff_ccfifo_extract(), but takes the raw bytes instead of an AVFrame.
Definition: ccfifo.c:154
len
int len
Definition: vorbis_enc_data.h:426
ff_ccfifo_init
int ff_ccfifo_init(CCFifo *ccf, AVRational framerate, void *log_ctx)
Initialize a CCFifo.
Definition: ccfifo.c:53
CCFifo::expected_cc_count
int expected_cc_count
Definition: ccfifo.h:44
CCFifo::cc_708_fifo
struct AVFifo * cc_708_fifo
Definition: ccfifo.h:42
CCFifo::log_ctx
void * log_ctx
Definition: ccfifo.h:49
ff_ccfifo_extract
int ff_ccfifo_extract(CCFifo *ccf, AVFrame *frame)
Extract CC data from an AVFrame.
Definition: ccfifo.c:183
ff_ccfifo_ccdetected
static int ff_ccfifo_ccdetected(const CCFifo *ccf)
Returns 1 if captions have been found as a prior call to ff_ccfifo_extract() or ff_ccfifo_extractbyte...
Definition: ccfifo.h:124
CCFifo::passthrough_warning
int passthrough_warning
Definition: ccfifo.h:48