--- /dev/null
+/*
+ * ARIB STD-B24 caption decoder using the libaribb24 library
+ * Copyright (c) 2019 Jan Ekström
+ *
+ * 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 "avcodec.h"
+#include "libavcodec/ass.h"
+#include "libavutil/log.h"
+#include "libavutil/opt.h"
+
+#include <aribb24/aribb24.h>
+#include <aribb24/parser.h>
+#include <aribb24/decoder.h>
+
+typedef struct Libaribb24Context {
+ AVClass *class;
+
+ arib_instance_t *lib_instance;
+ arib_parser_t *parser;
+ arib_decoder_t *decoder;
+
+ int read_order;
+
+ char *aribb24_base_path;
+ unsigned int aribb24_skip_ruby;
+} Libaribb24Context;
+
+static unsigned int get_profile_font_size(int profile)
+{
+ switch (profile) {
+ case FF_PROFILE_ARIB_PROFILE_A:
+ return 36;
+ case FF_PROFILE_ARIB_PROFILE_C:
+ return 18;
+ default:
+ return 0;
+ }
+}
+
+static void libaribb24_log(void *p, const char *msg)
+{
+ av_log((AVCodecContext *)p, AV_LOG_INFO, "%s\n", msg);
+}
+
+static int libaribb24_generate_ass_header(AVCodecContext *avctx)
+{
+ unsigned int plane_width = 0;
+ unsigned int plane_height = 0;
+ unsigned int font_size = 0;
+
+ switch (avctx->profile) {
+ case FF_PROFILE_ARIB_PROFILE_A:
+ plane_width = 960;
+ plane_height = 540;
+ font_size = get_profile_font_size(avctx->profile);
+ break;
+ case FF_PROFILE_ARIB_PROFILE_C:
+ plane_width = 320;
+ plane_height = 180;
+ font_size = get_profile_font_size(avctx->profile);
+ break;
+ default:
+ av_log(avctx, AV_LOG_ERROR, "Unknown or unsupported profile set!\n");
+ return AVERROR(EINVAL);
+ }
+
+ avctx->subtitle_header = av_asprintf(
+ "[Script Info]\r\n"
+ "; Script generated by FFmpeg/Lavc%s\r\n"
+ "ScriptType: v4.00+\r\n"
+ "PlayResX: %d\r\n"
+ "PlayResY: %d\r\n"
+ "\r\n"
+ "[V4+ Styles]\r\n"
+
+ /* ASSv4 header */
+ "Format: Name, "
+ "Fontname, Fontsize, "
+ "PrimaryColour, SecondaryColour, OutlineColour, BackColour, "
+ "Bold, Italic, Underline, StrikeOut, "
+ "ScaleX, ScaleY, "
+ "Spacing, Angle, "
+ "BorderStyle, Outline, Shadow, "
+ "Alignment, MarginL, MarginR, MarginV, "
+ "Encoding\r\n"
+
+ "Style: "
+ "Default," /* Name */
+ "%s,%d," /* Font{name,size} */
+ "&H%x,&H%x,&H%x,&H%x," /* {Primary,Secondary,Outline,Back}Colour */
+ "%d,%d,%d,0," /* Bold, Italic, Underline, StrikeOut */
+ "100,100," /* Scale{X,Y} */
+ "0,0," /* Spacing, Angle */
+ "%d,1,0," /* BorderStyle, Outline, Shadow */
+ "%d,10,10,10," /* Alignment, Margin[LRV] */
+ "0\r\n" /* Encoding */
+
+ "\r\n"
+ "[Events]\r\n"
+ "Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n",
+ !(avctx->flags & AV_CODEC_FLAG_BITEXACT) ? AV_STRINGIFY(LIBAVCODEC_VERSION) : "",
+ plane_width, plane_height,
+ ASS_DEFAULT_FONT, font_size, ASS_DEFAULT_COLOR,
+ ASS_DEFAULT_COLOR, ASS_DEFAULT_BACK_COLOR, ASS_DEFAULT_BACK_COLOR,
+ -ASS_DEFAULT_BOLD, -ASS_DEFAULT_ITALIC, -ASS_DEFAULT_UNDERLINE,
+ ASS_DEFAULT_BORDERSTYLE, ASS_DEFAULT_ALIGNMENT);
+
+ if (!avctx->subtitle_header)
+ return AVERROR(ENOMEM);
+
+ avctx->subtitle_header_size = strlen(avctx->subtitle_header);
+
+ return 0;
+}
+
+static int libaribb24_init(AVCodecContext *avctx)
+{
+ Libaribb24Context *b24 = avctx->priv_data;
+ void(* arib_dec_init)(arib_decoder_t* decoder) = NULL;
+ int ret_code = AVERROR_EXTERNAL;
+
+ if (!(b24->lib_instance = arib_instance_new(avctx))) {
+ av_log(avctx, AV_LOG_ERROR, "Failed to initialize libaribb24!\n");
+ goto init_fail;
+ }
+
+ if (b24->aribb24_base_path) {
+ av_log(avctx, AV_LOG_INFO, "Setting the libaribb24 base path to '%s'\n",
+ b24->aribb24_base_path);
+ arib_set_base_path(b24->lib_instance, b24->aribb24_base_path);
+ }
+
+ arib_register_messages_callback(b24->lib_instance, libaribb24_log);
+
+ if (!(b24->parser = arib_get_parser(b24->lib_instance))) {
+ av_log(avctx, AV_LOG_ERROR, "Failed to initialize libaribb24 PES parser!\n");
+ goto init_fail;
+ }
+ if (!(b24->decoder = arib_get_decoder(b24->lib_instance))) {
+ av_log(avctx, AV_LOG_ERROR, "Failed to initialize libaribb24 decoder!\n");
+ goto init_fail;
+ }
+
+ switch (avctx->profile) {
+ case FF_PROFILE_ARIB_PROFILE_A:
+ arib_dec_init = arib_initialize_decoder_a_profile;
+ break;
+ case FF_PROFILE_ARIB_PROFILE_C:
+ arib_dec_init = arib_initialize_decoder_c_profile;
+ break;
+ default:
+ av_log(avctx, AV_LOG_ERROR, "Unknown or unsupported profile set!\n");
+ ret_code = AVERROR(EINVAL);
+ goto init_fail;
+ }
+
+ arib_dec_init(b24->decoder);
+
+ if (libaribb24_generate_ass_header(avctx) < 0) {
+ ret_code = AVERROR(ENOMEM);
+ goto init_fail;
+ }
+
+ return 0;
+
+init_fail:
+ if (b24->decoder)
+ arib_finalize_decoder(b24->decoder);
+
+ if (b24->lib_instance)
+ arib_instance_destroy(b24->lib_instance);
+
+ return ret_code;
+}
+
+static int libaribb24_close(AVCodecContext *avctx)
+{
+ Libaribb24Context *b24 = avctx->priv_data;
+
+ if (b24->decoder)
+ arib_finalize_decoder(b24->decoder);
+
+ if (b24->lib_instance)
+ arib_instance_destroy(b24->lib_instance);
+
+ return 0;
+}
+
+#define RGB_TO_BGR(c) ((c & 0xff) << 16 | (c & 0xff00) | ((c >> 16) & 0xff))
+
+static void libaribb24_handle_regions(AVCodecContext *avctx, AVSubtitle *sub)
+{
+ Libaribb24Context *b24 = avctx->priv_data;
+ const arib_buf_region_t *region = arib_decoder_get_regions(b24->decoder);
+ unsigned int profile_font_size = get_profile_font_size(avctx->profile);
+ AVBPrint buf = { 0 };
+
+ av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+
+ while (region) {
+ ptrdiff_t region_length = region->p_end - region->p_start;
+ unsigned int ruby_region =
+ region->i_fontheight == (profile_font_size / 2);
+
+ // ASS requires us to make the colors BGR, so we convert here
+ int foreground_bgr_color = RGB_TO_BGR(region->i_foreground_color);
+ int background_bgr_color = RGB_TO_BGR(region->i_background_color);
+
+ if (region_length < 0) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid negative region length!\n");
+ break;
+ }
+
+ if (region_length == 0 || (ruby_region && b24->aribb24_skip_ruby)) {
+ goto next_region;
+ }
+
+ // color and alpha
+ if (foreground_bgr_color != ASS_DEFAULT_COLOR)
+ av_bprintf(&buf, "{\\1c&H%06x&}", foreground_bgr_color);
+
+ if (region->i_foreground_alpha != 0)
+ av_bprintf(&buf, "{\\1a&H%02x&}", region->i_foreground_alpha);
+
+ if (background_bgr_color != ASS_DEFAULT_BACK_COLOR)
+ av_bprintf(&buf, "{\\3c&H%06x&}", background_bgr_color);
+
+ if (region->i_background_alpha != 0)
+ av_bprintf(&buf, "{\\3a&H%02x&}", region->i_background_alpha);
+
+ // font size
+ if (region->i_fontwidth != profile_font_size ||
+ region->i_fontheight != profile_font_size) {
+ av_bprintf(&buf, "{\\fscx%d\\fscy%d}",
+ (int)round(((double)region->i_fontwidth /
+ (double)profile_font_size) * 100),
+ (int)round(((double)region->i_fontheight /
+ (double)profile_font_size) * 100));
+ }
+
+ // TODO: positioning
+
+ av_bprint_append_data(&buf, region->p_start, region_length);
+
+ av_bprintf(&buf, "{\\r}");
+
+next_region:
+ region = region->p_next;
+ }
+
+ av_log(avctx, AV_LOG_DEBUG, "Styled ASS line: %s\n",
+ buf.str);
+ ff_ass_add_rect(sub, buf.str, b24->read_order++,
+ 0, NULL, NULL);
+
+ av_bprint_finalize(&buf, NULL);
+}
+
+static int libaribb24_decode(AVCodecContext *avctx, void *data, int *got_sub_ptr, AVPacket *pkt)
+{
+ Libaribb24Context *b24 = avctx->priv_data;
+ AVSubtitle *sub = data;
+ size_t parsed_data_size = 0;
+ size_t decoded_subtitle_size = 0;
+ const unsigned char *parsed_data = NULL;
+ char *decoded_subtitle = NULL;
+ time_t subtitle_duration = 0;
+
+ if (pkt->size <= 0)
+ return pkt->size;
+
+ arib_parse_pes(b24->parser, pkt->data, pkt->size);
+
+ parsed_data = arib_parser_get_data(b24->parser,
+ &parsed_data_size);
+ if (!parsed_data || !parsed_data_size) {
+ av_log(avctx, AV_LOG_DEBUG, "No decode'able data was received from "
+ "packet (dts: %"PRId64", pts: %"PRId64").\n",
+ pkt->dts, pkt->pts);
+ return pkt->size;
+ }
+
+ decoded_subtitle_size = parsed_data_size * 4;
+ if (!(decoded_subtitle = av_mallocz(decoded_subtitle_size + 1))) {
+ av_log(avctx, AV_LOG_ERROR,
+ "Failed to allocate buffer for decoded subtitle!\n");
+ return AVERROR(ENOMEM);
+ }
+
+ decoded_subtitle_size = arib_decode_buffer(b24->decoder,
+ parsed_data,
+ parsed_data_size,
+ decoded_subtitle,
+ decoded_subtitle_size);
+
+ subtitle_duration = arib_decoder_get_time(b24->decoder);
+
+ if (avctx->pkt_timebase.num && pkt->pts != AV_NOPTS_VALUE)
+ sub->pts = av_rescale_q(pkt->pts,
+ avctx->pkt_timebase, AV_TIME_BASE_Q);
+
+ sub->end_display_time = subtitle_duration ?
+ av_rescale_q(subtitle_duration,
+ AV_TIME_BASE_Q,
+ (AVRational){1, 1000}) :
+ UINT32_MAX;
+
+ av_log(avctx, AV_LOG_DEBUG,
+ "Result: '%s' (size: %zu, pkt_pts: %"PRId64", sub_pts: %"PRId64" "
+ "duration: %"PRIu32", pkt_timebase: %d/%d, time_base: %d/%d')\n",
+ decoded_subtitle ? decoded_subtitle : "<no subtitle>",
+ decoded_subtitle_size,
+ pkt->pts, sub->pts,
+ sub->end_display_time,
+ avctx->pkt_timebase.num, avctx->pkt_timebase.den,
+ avctx->time_base.num, avctx->time_base.den);
+
+ if (decoded_subtitle)
+ libaribb24_handle_regions(avctx, sub);
+
+ *got_sub_ptr = sub->num_rects > 0;
+
+ av_free(decoded_subtitle);
+
+ // flush the region buffers, otherwise the linked list keeps getting
+ // longer and longer...
+ arib_finalize_decoder(b24->decoder);
+
+ return pkt->size;
+}
+
+static void libaribb24_flush(AVCodecContext *avctx)
+{
+ Libaribb24Context *b24 = avctx->priv_data;
+ if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
+ b24->read_order = 0;
+}
+
+#define OFFSET(x) offsetof(Libaribb24Context, x)
+#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
+static const AVOption options[] = {
+ { "aribb24-base-path", "set the base path for the libaribb24 library",
+ OFFSET(aribb24_base_path), AV_OPT_TYPE_STRING, { 0 }, 0, 0, SD },
+ { "aribb24-skip-ruby-text", "skip ruby text blocks during decoding",
+ OFFSET(aribb24_skip_ruby), AV_OPT_TYPE_BOOL, { 1 }, 0, 1, SD },
+ { NULL }
+};
+
+static const AVClass aribb24_class = {
+ .class_name = "libaribb24 decoder",
+ .item_name = av_default_item_name,
+ .option = options,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
+AVCodec ff_libaribb24_decoder = {
+ .name = "libaribb24",
+ .long_name = NULL_IF_CONFIG_SMALL("libaribb24 ARIB STD-B24 caption decoder"),
+ .type = AVMEDIA_TYPE_SUBTITLE,
+ .id = AV_CODEC_ID_ARIB_CAPTION,
+ .priv_data_size = sizeof(Libaribb24Context),
+ .init = libaribb24_init,
+ .close = libaribb24_close,
+ .decode = libaribb24_decode,
+ .flush = libaribb24_flush,
+ .priv_class= &aribb24_class,
+ .wrapper_name = "libaribb24",
+};
projects / ffmpeg / commitdiff