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insert a dummy frame before changing clips (still no major improvement), back to the previous frame search algorithm because the talkbox clips can be quite different

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4449 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jörg Hohensohn 2004-03-29 08:19:47 +00:00
parent 39c07cdcfb
commit b109c1e910
1 changed files with 19 additions and 11 deletions
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30
apps/talk.c
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@ -167,14 +167,11 @@ static int shutup(void)
unsigned char* pos;
unsigned char* search;
unsigned char* end;
unsigned char frame1, frame3;
unsigned char *firstclip = mp3buf + p_voicefont->index[0].offset;
/* We use the first frame in the thumbnail buffer as a template
for finding headers, assuming that all thumbnails are encoded
with the same parameters */
frame1 = firstclip[1]; /* second byte of the first mp3 header */
frame3 = firstclip[3]; /* last byte of the first mp3 header */
/* one silent bitswapped mp3 frame (22kHz), without bit reservoir */
static const unsigned char silent_frame[] = {
0xFF,0xCF,0x08,0x23,0x00,0x00,0x00,0xC0,0x12,0x80,0x01,0x00,0x00,
0x32,0x82,0xB2,0xA2,0xCC,0x74,0x9C,0xCC,0xAA,0xAA,0xAA,0xAA,0xAA,
};
mp3_play_pause(false); /* pause */
@ -188,11 +185,21 @@ static int shutup(void)
/* Find the next frame boundary */
while (search < end) /* search the remaining data */
{
if(search[0] == 0xff && search[1] == frame1 && search[3] == frame3)
if (*search++ != 0xFF) /* search for frame sync byte */
{
break;
continue;
}
/* look at the (bitswapped) 2nd byte of header candidate */
if ((*search & 0x07) == 0x07 /* rest of frame sync */
&& (*search & 0x18) != 0x10 /* version != reserved */
&& (*search & 0x60) != 0x00) /* layer != reserved */
{
search--; /* back to the sync byte */
break; /* From looking at the first 2 bytes, this is a header. */
/* this is not a sufficient condition to find header,
may give "false alert" (end too early), but a start */
}
search++;
}
queue_write = queue_read; /* reset the queue */
@ -204,6 +211,7 @@ static int shutup(void)
/* If the voice clips contain dependent frames (currently they don't),
it may be a good idea to insert an independent dummy frame here. */
queue_clip((unsigned char*)silent_frame, sizeof(silent_frame), true);
return 0;
}