corresponding AVMEDIA_TYPE_* symbols. Originally committed as revision 25201 to svn://svn.ffmpeg.org/ffmpeg/trunk
		
			
				
	
	
		
			136 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			136 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Tele-typewriter demuxer
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|  * Copyright (c) 2010 Peter Ross <pross@xvid.org>
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| /**
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|  * @file
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|  * Tele-typewriter demuxer
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|  */
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| 
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| #include "libavutil/intreadwrite.h"
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| #include "libavutil/avstring.h"
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| #include "avformat.h"
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| #include "sauce.h"
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| #include <strings.h>
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| 
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| #define LINE_RATE 6000 /* characters per second */
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| 
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| typedef struct {
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|     int chars_per_frame;
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|     uint64_t fsize;  /**< file size less metadata buffer */
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| } TtyDemuxContext;
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| 
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| /**
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|  * Parse EFI header
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|  */
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| static int efi_read(AVFormatContext *avctx, uint64_t start_pos)
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| {
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|     TtyDemuxContext *s = avctx->priv_data;
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|     ByteIOContext *pb = avctx->pb;
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|     char buf[37];
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|     int len;
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| 
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|     url_fseek(pb, start_pos, SEEK_SET);
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|     if (get_byte(pb) != 0x1A)
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|         return -1;
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| 
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| #define GET_EFI_META(name,size) \
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|     len = get_byte(pb); \
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|     if (len < 1 || len > size) \
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|         return -1; \
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|     if (get_buffer(pb, buf, size) == size) { \
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|         buf[len] = 0; \
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|         av_metadata_set2(&avctx->metadata, name, buf, 0); \
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|     }
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| 
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|     GET_EFI_META("filename", 12)
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|     GET_EFI_META("title",    36)
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| 
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|     s->fsize = start_pos;
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|     return 0;
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| }
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| 
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| static int read_header(AVFormatContext *avctx,
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|                        AVFormatParameters *ap)
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| {
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|     TtyDemuxContext *s = avctx->priv_data;
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|     AVStream *st = av_new_stream(avctx, 0);
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|     if (!st)
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|         return AVERROR(ENOMEM);
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|     st->codec->codec_tag   = 0;
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|     st->codec->codec_type  = AVMEDIA_TYPE_VIDEO;
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|     st->codec->codec_id    = CODEC_ID_ANSI;
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|     if (ap->width)  st->codec->width  = ap->width;
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|     if (ap->height) st->codec->height = ap->height;
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| 
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|     if (!ap->time_base.num) {
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|         av_set_pts_info(st, 60, 1, 25);
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|     } else {
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|         av_set_pts_info(st, 60, ap->time_base.num, ap->time_base.den);
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|     }
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| 
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|     /* simulate tty display speed */
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|     s->chars_per_frame = FFMAX(av_q2d(st->time_base) * (ap->sample_rate ? ap->sample_rate : LINE_RATE), 1);
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| 
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|     if (!url_is_streamed(avctx->pb)) {
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|         s->fsize = url_fsize(avctx->pb);
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|         st->duration = (s->fsize + s->chars_per_frame - 1) / s->chars_per_frame;
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| 
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|         if (ff_sauce_read(avctx, &s->fsize, 0, 0) < 0)
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|             efi_read(avctx, s->fsize - 51);
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| 
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|         url_fseek(avctx->pb, 0, SEEK_SET);
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|     }
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| 
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|     return 0;
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| }
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| 
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| static int read_packet(AVFormatContext *avctx, AVPacket *pkt)
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| {
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|     TtyDemuxContext *s = avctx->priv_data;
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|     int n;
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| 
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|     if (url_feof(avctx->pb))
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|         return AVERROR_EOF;
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| 
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|     n = s->chars_per_frame;
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|     if (s->fsize) {
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|         // ignore metadata buffer
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|         uint64_t p = url_ftell(avctx->pb);
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|         if (p + s->chars_per_frame > s->fsize)
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|             n = s->fsize - p;
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|     }
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| 
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|     pkt->size = av_get_packet(avctx->pb, pkt, n);
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|     if (pkt->size <= 0)
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|         return AVERROR(EIO);
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|     pkt->flags |= PKT_FLAG_KEY;
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|     return 0;
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| }
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| 
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| AVInputFormat tty_demuxer = {
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|     .name           = "tty",
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|     .long_name      = NULL_IF_CONFIG_SMALL("Tele-typewriter"),
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|     .priv_data_size = sizeof(TtyDemuxContext),
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|     .read_header    = read_header,
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|     .read_packet    = read_packet,
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|     .extensions     = "ans,art,asc,diz,ice,nfo,txt,vt",
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| };
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