/* * CEA-708 Closed Captioning FIFO * Copyright (c) 2023 LTN Global Communications * * Author: Devin Heitmueller <dheitmueller@ltnglobal.com> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * CC FIFO Buffer */ #ifndef AVFILTER_CCFIFO_H#define AVFILTER_CCFIFO_H #include <stddef.h>#include <stdint.h> #include "libavutil/frame.h"#include "libavutil/rational.h" #define CC_BYTES_PER_ENTRY 3 typedef struct CCFifo {    struct AVFifo *cc_608_fifo;    struct AVFifo *cc_708_fifo;    AVRational framerate;    int expected_cc_count;    int expected_608;    int cc_detected;    int passthrough;    int passthrough_warning;    void *log_ctx;} CCFifo; /** * Initialize a CCFifo. * * @param framerate   output framerate * @param log_ctx     used for any av_log() calls * @return            Zero on success, or negative AVERROR code on failure. */int ff_ccfifo_init(CCFifo *ccf, AVRational framerate, void *log_ctx); /** * Free all memory allocated in a CCFifo and clear the context. * * @param ccf Pointer to the CCFifo which should be uninitialized */void ff_ccfifo_uninit(CCFifo *ccf); /** * Extract CC data from an AVFrame * * Extract CC bytes from the AVFrame, insert them into our queue, and * remove the side data from the AVFrame.  The side data is removed * as it will be re-inserted at the appropriate rate later in the * filter. * * @param af          CCFifo to write to * @param frame       AVFrame with the video frame to operate on * @return            Zero on success, or negative AVERROR *                    code on failure. */int ff_ccfifo_extract(CCFifo *ccf, AVFrame *frame); /** *Just like ff_ccfifo_extract(), but takes the raw bytes instead of an AVFrame */int ff_ccfifo_extractbytes(CCFifo *ccf, uint8_t *data, size_t len); /** * Provide the size in bytes of an output buffer to allocate * * Ask for how many bytes the output will contain, so the caller can allocate * an appropriately sized buffer and pass it to ff_ccfifo_injectbytes() * */static inline int ff_ccfifo_getoutputsize(const CCFifo *ccf){    return ccf->expected_cc_count * CC_BYTES_PER_ENTRY;}  /** * Insert CC data from the FIFO into an AVFrame (as side data) * * Dequeue the appropriate number of CC tuples based on the * frame rate, and insert them into the AVFrame * * @param af          CCFifo to read from * @param frame       AVFrame with the video frame to operate on * @return            Zero on success, or negative AVERROR *                    code on failure. */int ff_ccfifo_inject(CCFifo *ccf, AVFrame *frame); /** * Just like ff_ccfifo_inject(), but takes the raw bytes to insert the CC data * int rather than an AVFrame */int ff_ccfifo_injectbytes(CCFifo *ccf, uint8_t *data, size_t len); /** * Returns 1 if captions have been found as a prior call * to ff_ccfifo_extract() or ff_ccfifo_extractbytes() */static inline int ff_ccfifo_ccdetected(const CCFifo *ccf){    return ccf->cc_detected;} #endif /* AVFILTER_CCFIFO_H */