This commit does for AVOutputFormat what commit 20f972701806be20a77f808db332d9489343bb78 did for AVCodec: It adds a new type FFOutputFormat, moves all the internals of AVOutputFormat to it and adds a now reduced AVOutputFormat as first member. This does not affect/improve extensibility of both public or private fields for muxers (it is still a mess due to lavd). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> Signed-off-by: Anton Khirnov <anton@khirnov.net>
		
			
				
	
	
		
			232 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			232 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * TTML subtitle muxer
 | |
|  * Copyright (c) 2020 24i
 | |
|  *
 | |
|  * 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
 | |
|  * TTML subtitle muxer
 | |
|  * @see https://www.w3.org/TR/ttml1/
 | |
|  * @see https://www.w3.org/TR/ttml2/
 | |
|  * @see https://www.w3.org/TR/ttml-imsc/rec
 | |
|  */
 | |
| 
 | |
| #include "libavutil/avstring.h"
 | |
| #include "avformat.h"
 | |
| #include "internal.h"
 | |
| #include "mux.h"
 | |
| #include "ttmlenc.h"
 | |
| #include "libavcodec/ttmlenc.h"
 | |
| #include "libavutil/internal.h"
 | |
| 
 | |
| enum TTMLPacketType {
 | |
|     PACKET_TYPE_PARAGRAPH,
 | |
|     PACKET_TYPE_DOCUMENT,
 | |
| };
 | |
| 
 | |
| struct TTMLHeaderParameters {
 | |
|     const char *tt_element_params;
 | |
|     const char *pre_body_elements;
 | |
| };
 | |
| 
 | |
| typedef struct TTMLMuxContext {
 | |
|     enum TTMLPacketType input_type;
 | |
|     unsigned int document_written;
 | |
| } TTMLMuxContext;
 | |
| 
 | |
| static const char ttml_header_text[] =
 | |
| "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n"
 | |
| "<tt\n"
 | |
| "%s"
 | |
| "  xml:lang=\"%s\">\n"
 | |
| "%s"
 | |
| "  <body>\n"
 | |
| "    <div>\n";
 | |
| 
 | |
| static const char ttml_footer_text[] =
 | |
| "    </div>\n"
 | |
| "  </body>\n"
 | |
| "</tt>\n";
 | |
| 
 | |
| static void ttml_write_time(AVIOContext *pb, const char tag[],
 | |
|                             int64_t millisec)
 | |
| {
 | |
|     int64_t sec, min, hour;
 | |
|     sec = millisec / 1000;
 | |
|     millisec -= 1000 * sec;
 | |
|     min = sec / 60;
 | |
|     sec -= 60 * min;
 | |
|     hour = min / 60;
 | |
|     min -= 60 * hour;
 | |
| 
 | |
|     avio_printf(pb, "%s=\"%02"PRId64":%02"PRId64":%02"PRId64".%03"PRId64"\"",
 | |
|                 tag, hour, min, sec, millisec);
 | |
| }
 | |
| 
 | |
| static int ttml_set_header_values_from_extradata(
 | |
|     AVCodecParameters *par, struct TTMLHeaderParameters *header_params)
 | |
| {
 | |
|     size_t additional_data_size =
 | |
|         par->extradata_size - TTMLENC_EXTRADATA_SIGNATURE_SIZE;
 | |
|     char *value =
 | |
|         (char *)par->extradata + TTMLENC_EXTRADATA_SIGNATURE_SIZE;
 | |
|     size_t value_size = av_strnlen(value, additional_data_size);
 | |
|     struct TTMLHeaderParameters local_params = { 0 };
 | |
| 
 | |
|     if (!additional_data_size) {
 | |
|         // simple case, we don't have to go through local_params and just
 | |
|         // set default fall-back values (for old extradata format).
 | |
|         header_params->tt_element_params = TTML_DEFAULT_NAMESPACING;
 | |
|         header_params->pre_body_elements = "";
 | |
| 
 | |
|         return 0;
 | |
|     }
 | |
| 
 | |
|     if (value_size == additional_data_size ||
 | |
|         value[value_size] != '\0')
 | |
|         return AVERROR_INVALIDDATA;
 | |
| 
 | |
|     local_params.tt_element_params = value;
 | |
| 
 | |
|     additional_data_size -= value_size + 1;
 | |
|     value += value_size + 1;
 | |
|     if (!additional_data_size)
 | |
|         return AVERROR_INVALIDDATA;
 | |
| 
 | |
|     value_size = av_strnlen(value, additional_data_size);
 | |
|     if (value_size == additional_data_size ||
 | |
|         value[value_size] != '\0')
 | |
|         return AVERROR_INVALIDDATA;
 | |
| 
 | |
|     local_params.pre_body_elements = value;
 | |
| 
 | |
|     *header_params = local_params;
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static int ttml_write_header(AVFormatContext *ctx)
 | |
| {
 | |
|     TTMLMuxContext *ttml_ctx = ctx->priv_data;
 | |
|     ttml_ctx->document_written = 0;
 | |
| 
 | |
|     if (ctx->nb_streams != 1 ||
 | |
|         ctx->streams[0]->codecpar->codec_id != AV_CODEC_ID_TTML) {
 | |
|         av_log(ctx, AV_LOG_ERROR, "Exactly one TTML stream is required!\n");
 | |
|         return AVERROR(EINVAL);
 | |
|     }
 | |
| 
 | |
|     {
 | |
|         AVStream    *st = ctx->streams[0];
 | |
|         AVIOContext *pb = ctx->pb;
 | |
| 
 | |
|         AVDictionaryEntry *lang = av_dict_get(st->metadata, "language", NULL,
 | |
|                                               0);
 | |
|         const char *printed_lang = (lang && lang->value) ? lang->value : "";
 | |
| 
 | |
|         ttml_ctx->input_type = ff_is_ttml_stream_paragraph_based(st->codecpar) ?
 | |
|                                PACKET_TYPE_PARAGRAPH :
 | |
|                                PACKET_TYPE_DOCUMENT;
 | |
| 
 | |
|         avpriv_set_pts_info(st, 64, 1, 1000);
 | |
| 
 | |
|         if (ttml_ctx->input_type == PACKET_TYPE_PARAGRAPH) {
 | |
|             struct TTMLHeaderParameters header_params;
 | |
|             int ret = ttml_set_header_values_from_extradata(
 | |
|                 st->codecpar, &header_params);
 | |
|             if (ret < 0) {
 | |
|                 av_log(ctx, AV_LOG_ERROR,
 | |
|                        "Failed to parse TTML header values from extradata: "
 | |
|                        "%s!\n", av_err2str(ret));
 | |
|                 return ret;
 | |
|             }
 | |
| 
 | |
|             avio_printf(pb, ttml_header_text,
 | |
|                         header_params.tt_element_params,
 | |
|                         printed_lang,
 | |
|                         header_params.pre_body_elements);
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static int ttml_write_packet(AVFormatContext *ctx, AVPacket *pkt)
 | |
| {
 | |
|     TTMLMuxContext *ttml_ctx = ctx->priv_data;
 | |
|     AVIOContext    *pb       = ctx->pb;
 | |
| 
 | |
|     switch (ttml_ctx->input_type) {
 | |
|     case PACKET_TYPE_PARAGRAPH:
 | |
|         // write out a paragraph element with the given contents.
 | |
|         avio_printf(pb,     "      <p\n");
 | |
|         ttml_write_time(pb, "        begin", pkt->pts);
 | |
|         avio_w8(pb, '\n');
 | |
|         ttml_write_time(pb, "        end",   pkt->pts + pkt->duration);
 | |
|         avio_printf(pb, ">");
 | |
|         avio_write(pb, pkt->data, pkt->size);
 | |
|         avio_printf(pb, "</p>\n");
 | |
|         break;
 | |
|     case PACKET_TYPE_DOCUMENT:
 | |
|         // dump the given document out as-is.
 | |
|         if (ttml_ctx->document_written) {
 | |
|             av_log(ctx, AV_LOG_ERROR,
 | |
|                    "Attempting to write multiple TTML documents into a "
 | |
|                    "single document! The XML specification forbids this "
 | |
|                    "as there has to be a single root tag.\n");
 | |
|             return AVERROR(EINVAL);
 | |
|         }
 | |
|         avio_write(pb, pkt->data, pkt->size);
 | |
|         ttml_ctx->document_written = 1;
 | |
|         break;
 | |
|     default:
 | |
|         av_log(ctx, AV_LOG_ERROR,
 | |
|                "Internal error: invalid TTML input packet type: %d!\n",
 | |
|                ttml_ctx->input_type);
 | |
|         return AVERROR_BUG;
 | |
|     }
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static int ttml_write_trailer(AVFormatContext *ctx)
 | |
| {
 | |
|     TTMLMuxContext *ttml_ctx = ctx->priv_data;
 | |
|     AVIOContext    *pb       = ctx->pb;
 | |
| 
 | |
|     if (ttml_ctx->input_type == PACKET_TYPE_PARAGRAPH)
 | |
|         avio_printf(pb, ttml_footer_text);
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| const FFOutputFormat ff_ttml_muxer = {
 | |
|     .p.name            = "ttml",
 | |
|     .p.long_name       = NULL_IF_CONFIG_SMALL("TTML subtitle"),
 | |
|     .p.extensions      = "ttml",
 | |
|     .p.mime_type       = "text/ttml",
 | |
|     .priv_data_size    = sizeof(TTMLMuxContext),
 | |
|     .p.flags           = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS |
 | |
|                          AVFMT_TS_NONSTRICT,
 | |
|     .p.subtitle_codec  = AV_CODEC_ID_TTML,
 | |
|     .write_header      = ttml_write_header,
 | |
|     .write_packet      = ttml_write_packet,
 | |
|     .write_trailer     = ttml_write_trailer,
 | |
| };
 |