| /* |
| * 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 |
| */ |
| |
| #include "ccfifo.h" |
| #include "libavutil/fifo.h" |
| |
| #define MAX_CC_ELEMENTS 128 |
| |
| struct cc_lookup { |
| int num; |
| int den; |
| int cc_count; |
| int num_608; |
| }; |
| |
| const static struct cc_lookup cc_lookup_vals[] = { |
| { 15, 1, 40, 4 }, |
| { 24, 1, 25, 3 }, |
| { 24000, 1001, 25, 3 }, |
| { 30, 1, 20, 2 }, |
| { 30000, 1001, 20, 2}, |
| { 60, 1, 10, 1 }, |
| { 60000, 1001, 10, 1}, |
| }; |
| |
| void ff_ccfifo_uninit(CCFifo *ccf) |
| { |
| av_fifo_freep2(&ccf->cc_608_fifo); |
| av_fifo_freep2(&ccf->cc_708_fifo); |
| memset(ccf, 0, sizeof(*ccf)); |
| } |
| |
| int ff_ccfifo_init(CCFifo *ccf, AVRational framerate, void *log_ctx) |
| { |
| int i; |
| |
| memset(ccf, 0, sizeof(*ccf)); |
| ccf->log_ctx = log_ctx; |
| ccf->framerate = framerate; |
| |
| if (!(ccf->cc_708_fifo = av_fifo_alloc2(MAX_CC_ELEMENTS, CC_BYTES_PER_ENTRY, 0))) |
| goto error; |
| |
| if (!(ccf->cc_608_fifo = av_fifo_alloc2(MAX_CC_ELEMENTS, CC_BYTES_PER_ENTRY, 0))) |
| goto error; |
| |
| /* Based on the target FPS, figure out the expected cc_count and number of |
| 608 tuples per packet. See ANSI/CTA-708-E Sec 4.3.6.1. */ |
| for (i = 0; i < FF_ARRAY_ELEMS(cc_lookup_vals); i++) { |
| if (framerate.num == cc_lookup_vals[i].num && |
| framerate.den == cc_lookup_vals[i].den) { |
| ccf->expected_cc_count = cc_lookup_vals[i].cc_count; |
| ccf->expected_608 = cc_lookup_vals[i].num_608; |
| break; |
| } |
| } |
| |
| if (ccf->expected_608 == 0) { |
| /* We didn't find an output frame we support. We'll let the call succeed |
| and the FIFO to be allocated, but the extract/inject functions will simply |
| leave everything the way it is */ |
| ccf->passthrough = 1; |
| } |
| |
| return 0; |
| |
| error: |
| ff_ccfifo_uninit(ccf); |
| return AVERROR(ENOMEM); |
| } |
| |
| int ff_ccfifo_injectbytes(CCFifo *ccf, uint8_t *cc_data, size_t len) |
| { |
| int cc_608_tuples = 0; |
| int cc_708_tuples = 0; |
| int cc_filled = 0; |
| |
| if (ccf->passthrough) { |
| return 0; |
| } |
| |
| if (len < ff_ccfifo_getoutputsize(ccf)) { |
| return AVERROR(EINVAL); |
| } |
| |
| /* Insert any available data from the 608 FIFO */ |
| if (ccf->expected_608 <= av_fifo_can_read(ccf->cc_608_fifo)) |
| cc_608_tuples = ccf->expected_608; |
| else |
| cc_608_tuples = av_fifo_can_read(ccf->cc_608_fifo); |
| av_fifo_read(ccf->cc_608_fifo, cc_data, cc_608_tuples); |
| cc_filled += cc_608_tuples; |
| |
| /* Insert any available data from the 708 FIFO */ |
| if ((ccf->expected_cc_count - cc_filled) <= av_fifo_can_read(ccf->cc_708_fifo)) |
| cc_708_tuples = ccf->expected_cc_count - cc_filled; |
| else |
| cc_708_tuples = av_fifo_can_read(ccf->cc_708_fifo); |
| av_fifo_read(ccf->cc_708_fifo, &cc_data[cc_filled * CC_BYTES_PER_ENTRY], cc_708_tuples); |
| cc_filled += cc_708_tuples; |
| |
| /* Insert 708 padding into any remaining fields */ |
| while (cc_filled < ccf->expected_cc_count) { |
| cc_data[cc_filled * CC_BYTES_PER_ENTRY] = 0xfa; |
| cc_data[cc_filled * CC_BYTES_PER_ENTRY + 1] = 0x00; |
| cc_data[cc_filled * CC_BYTES_PER_ENTRY + 2] = 0x00; |
| cc_filled++; |
| } |
| |
| return 0; |
| } |
| |
| int ff_ccfifo_inject(CCFifo *ccf, AVFrame *frame) |
| { |
| AVFrameSideData *sd; |
| int ret; |
| |
| if (ccf->passthrough == 1 || ccf->cc_detected == 0) |
| return 0; |
| |
| sd = av_frame_new_side_data(frame, AV_FRAME_DATA_A53_CC, |
| ff_ccfifo_getoutputsize(ccf)); |
| if (sd) { |
| ret = ff_ccfifo_injectbytes(ccf, sd->data, sd->size); |
| if (ret < 0) { |
| av_frame_remove_side_data(frame, AV_FRAME_DATA_A53_CC); |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| int ff_ccfifo_extractbytes(CCFifo *ccf, uint8_t *cc_bytes, size_t len) |
| { |
| int cc_count = len / CC_BYTES_PER_ENTRY; |
| |
| if (ccf->passthrough == 1) { |
| av_log_once(ccf->log_ctx, AV_LOG_WARNING, AV_LOG_DEBUG, &ccf->passthrough_warning, |
| "cc_fifo cannot transcode captions fps=%d/%d\n", |
| ccf->framerate.num, ccf->framerate.den); |
| return 0; |
| } |
| |
| ccf->cc_detected = 1; |
| |
| for (int i = 0; i < cc_count; i++) { |
| /* See ANSI/CTA-708-E Sec 4.3, Table 3 */ |
| uint8_t cc_valid = (cc_bytes[CC_BYTES_PER_ENTRY*i] & 0x04) >> 2; |
| uint8_t cc_type = cc_bytes[CC_BYTES_PER_ENTRY*i] & 0x03; |
| if (cc_type == 0x00 || cc_type == 0x01) { |
| av_fifo_write(ccf->cc_608_fifo, &cc_bytes[CC_BYTES_PER_ENTRY*i], 1); |
| } else if (cc_valid && (cc_type == 0x02 || cc_type == 0x03)) { |
| av_fifo_write(ccf->cc_708_fifo, &cc_bytes[CC_BYTES_PER_ENTRY*i], 1); |
| } |
| } |
| return 0; |
| } |
| |
| /* Read the A53 side data, discard padding, and put 608/708 into |
| queues so we can ensure they get into the output frames at |
| the correct rate... */ |
| int ff_ccfifo_extract(CCFifo *ccf, AVFrame *frame) |
| { |
| AVFrameSideData *side_data = av_frame_get_side_data(frame, AV_FRAME_DATA_A53_CC); |
| if (side_data) { |
| ff_ccfifo_extractbytes(ccf, side_data->data, side_data->size); |
| |
| /* Remove the side data, as we will re-create it on the |
| output as needed */ |
| if (!ccf->passthrough) |
| av_frame_remove_side_data(frame, AV_FRAME_DATA_A53_CC); |
| } |
| return 0; |
| } |