len0rd/rockbox
1
0
Fork 1
mirror of https://github.com/Rockbox/rockbox.git synced 2025-12-09 13:15:18 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

Build librbcodec with DSP and metadata.

Browse source 
All associated files are moved to /lib/rbcodec.

Change-Id: I572ddd2b8a996aae1e98c081d06b1ed356dce222
This commit is contained in:
Sean Bartell 2011-06-24 01:25:21 -04:00 • committed by Nils Wallménius
parent 24bd9d5393
commit b5716df4cb
80 changed files with 97 additions and 112 deletions
Download patch file Download diff file Expand all files Collapse all files

193
lib/rbcodec/metadata/mp3.c Normal file
View file

@ -0,0 +1,193 @@
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Daniel Stenberg
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
/*
* Parts of this code has been stolen from the Ample project and was written
* by David H<EFBFBD>deman. It has since been extended and enhanced pretty much by
* all sorts of friendly Rockbox people.
*
*/
/* tagResolver and associated code copyright 2003 Thomas Paul Diffenbach
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include "string-extra.h"
#include "config.h"
#include "file.h"
#include "logf.h"
#include "system.h"
#include "metadata.h"
#include "mp3data.h"
#include "metadata_common.h"
#include "metadata_parsers.h"
/*
* Calculates the length (in milliseconds) of an MP3 file.
*
* Modified to only use integers.
*
* Arguments: file - the file to calculate the length upon
* entry - the entry to update with the length
*
* Returns: the song length in milliseconds,
* 0 means that it couldn't be calculated
*/
static int getsonglength(int fd, struct mp3entry *entry)
{
unsigned long filetime = 0;
struct mp3info info;
long bytecount;
/* Start searching after ID3v2 header */
if(-1 == lseek(fd, entry->id3v2len, SEEK_SET))
return 0;
bytecount = get_mp3file_info(fd, &info);
logf("Space between ID3V2 tag and first audio frame: 0x%lx bytes",
bytecount);
if(bytecount < 0)
return -1;
bytecount += entry->id3v2len;
/* Validate byte count, in case the file has been edited without
* updating the header.
*/
if (info.byte_count)
{
const unsigned long expected = entry->filesize - entry->id3v1len
- entry->id3v2len;
const unsigned long diff = MAX(10240, info.byte_count / 20);
if ((info.byte_count > expected + diff)
|| (info.byte_count < expected - diff))
{
logf("Note: info.byte_count differs from expected value by "
"%ld bytes", labs((long) (expected - info.byte_count)));
info.byte_count = 0;
info.frame_count = 0;
info.file_time = 0;
info.enc_padding = 0;
/* Even if the bitrate was based on "known bad" values, it
* should still be better for VBR files than using the bitrate
* of the first audio frame.
*/
}
}
entry->bitrate = info.bitrate;
entry->frequency = info.frequency;
entry->layer = info.layer;
switch(entry->layer) {
#if CONFIG_CODEC==SWCODEC
case 0:
entry->codectype=AFMT_MPA_L1;
break;
#endif
case 1:
entry->codectype=AFMT_MPA_L2;
break;
case 2:
entry->codectype=AFMT_MPA_L3;
break;
}
/* If the file time hasn't been established, this may be a fixed
rate MP3, so just use the default formula */
filetime = info.file_time;
if(filetime == 0)
{
/* Prevent a division by zero */
if (info.bitrate < 8)
filetime = 0;
else
filetime = (entry->filesize - bytecount) / (info.bitrate / 8);
/* bitrate is in kbps so this delivers milliseconds. Doing bitrate / 8
* instead of filesize * 8 is exact, because mpeg audio bitrates are
* always multiples of 8, and it avoids overflows. */
}
entry->frame_count = info.frame_count;
entry->vbr = info.is_vbr;
entry->has_toc = info.has_toc;
#if CONFIG_CODEC==SWCODEC
if (!entry->lead_trim)
entry->lead_trim = info.enc_delay;
if (!entry->tail_trim)
entry->tail_trim = info.enc_padding;
#endif
memcpy(entry->toc, info.toc, sizeof(info.toc));
/* Update the seek point for the first playable frame */
entry->first_frame_offset = bytecount;
logf("First frame is at %lx", entry->first_frame_offset);
return filetime;
}
/*
* Checks all relevant information (such as ID3v1 tag, ID3v2 tag, length etc)
* about an MP3 file and updates it's entry accordingly.
*
Note, that this returns true for successful, false for error! */
bool get_mp3_metadata(int fd, struct mp3entry *entry)
{
entry->title = NULL;
entry->filesize = filesize(fd);
entry->id3v2len = getid3v2len(fd);
entry->tracknum = 0;
entry->discnum = 0;
if (entry->id3v2len)
setid3v2title(fd, entry);
int len = getsonglength(fd, entry);
if (len < 0)
return false;
entry->length = len;
/* Subtract the meta information from the file size to get
the true size of the MP3 stream */
entry->filesize -= entry->first_frame_offset;
/* only seek to end of file if no id3v2 tags were found */
if (!entry->id3v2len) {
setid3v1title(fd, entry);
}
if(!entry->length || (entry->filesize < 8 ))
/* no song length or less than 8 bytes is hereby considered to be an
invalid mp3 and won't be played by us! */
return false;
return true;
}