shithub: mcfs

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matroska: add ASS subtitles extraction (no timestamps rewriting yet)

--- /dev/null

+++ b/ass.c

@@ -1,0 +1,41 @@

+#include <u.h>

+#include <libc.h>

+#include <bio.h>

+#include "common.h"

+#include "packet.h"

+

+static int

+sanitize(uchar *s, int sz)

+{

+	uchar *o, *i;

+

+	for(o = i = s; sz > 0;){

+		if(*i == '\r'){

+			if(sz <= 1 || i[1] != '\n')

+				*o++ = '\n';

+			i++;

+		}else

+			*o++ = *i++;

+		sz--;

+	}

+

+	return o-s;

+}

+

+int

+asspacket(Biobuf *out, Packetctx *ctx, Packet *p, int np, uvlong ts, int key)

+{

+	int i;

+

+	USED(ts, key);

+	if(ctx->frid == 0)

+		Bwrite(out, ctx->codec.priv.data, sanitize(ctx->codec.priv.data, ctx->codec.priv.sz));

+	for(i = 0; i < np; i++, p++){

+		Bwrite(out, p->data, sanitize(p->data, p->sz));

+		Bwrite(out, "\n", 1);

+	}

+	ctx->frid++;

+	Bflush(out);

+

+	return 0;

+}

--- a/common.h

+++ b/common.h

@@ -16,6 +16,7 @@

 	FmtMp3 = 0x006d7033u,

 	FmtTheora = 0x74687261u,

 	FmtFlac = 0x666c6163u,

+	FmtAss = 0x00617373u, /* ass subtitles */

 };

 #define min(a,b) ((a)<=(b)?(a):(b))

--- a/matroska.c

+++ b/matroska.c

@@ -85,6 +85,8 @@

 	if(e->tracktype == Etracksubtitles){

 		if(strcmp(e->codec.name, "S_TEXT/UTF8") == 0)

 			return "srt";

+		else if(strcmp(e->codec.name, "S_TEXT/ASS") == 0)

+			return "ass";

 	}else if(e->tracktype == Etrackaudio){

 		if(strcmp(e->codec.name, "A_MPEG/L3") == 0)

 			return "mp3";

@@ -162,6 +164,9 @@

 		if(strcmp(c, "srt") == 0){

 			e->fmt = FmtSrt;

 			e->fpacket = srtpacket;

+		}else if(strcmp(c, "ass") == 0){

+			e->fmt = FmtAss;

+			e->fpacket = asspacket;

 		}else

 			goto err;

 		return 0;

--- a/mkfile

+++ b/mkfile

@@ -6,6 +6,7 @@

 OFILES=\

 	aac.$O\

+	ass.$O\

 	crc32.$O\

 	ebml.$O\

 	iso.$O\

--- a/packet.h

+++ b/packet.h

@@ -53,6 +53,7 @@

 };

 int aacpacket(Biobuf *out, Packetctx *ctx, Packet *p, int np, uvlong ts, int key);

+int asspacket(Biobuf *out, Packetctx *ctx, Packet *p, int np, uvlong ts, int key);

 int ivfpacket(Biobuf *out, Packetctx *ctx, Packet *p, int np, uvlong ts, int key);

 int oggpacket(Biobuf *out, Packetctx *ctx, Packet *p, int np, uvlong ts, int key);

 int srtpacket(Biobuf *out, Packetctx *ctx, Packet *p, int np, uvlong ts, int key);