rockbox/apps/metadata/mp4.c
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

726 lines
21 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 Magnus Holmgren
*
* 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.
*
****************************************************************************/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <inttypes.h>
#include "system.h"
#include "errno.h"
#include "id3.h"
#include "metadata_common.h"
#include "metadata_parsers.h"
#include "logf.h"
#include "debug.h"
#include "replaygain.h"
#define MP4_ID(a, b, c, d) (((a) << 24) | ((b) << 16) | ((c) << 8) | (d))
#define MP4_3gp6 MP4_ID('3', 'g', 'p', '6')
#define MP4_aART MP4_ID('a', 'A', 'R', 'T')
#define MP4_alac MP4_ID('a', 'l', 'a', 'c')
#define MP4_calb MP4_ID(0xa9, 'a', 'l', 'b')
#define MP4_cART MP4_ID(0xa9, 'A', 'R', 'T')
#define MP4_cgrp MP4_ID(0xa9, 'g', 'r', 'p')
#define MP4_cgen MP4_ID(0xa9, 'g', 'e', 'n')
#define MP4_cnam MP4_ID(0xa9, 'n', 'a', 'm')
#define MP4_cwrt MP4_ID(0xa9, 'w', 'r', 't')
#define MP4_ccmt MP4_ID(0xa9, 'c', 'm', 't')
#define MP4_cday MP4_ID(0xa9, 'd', 'a', 'y')
#define MP4_disk MP4_ID('d', 'i', 's', 'k')
#define MP4_esds MP4_ID('e', 's', 'd', 's')
#define MP4_ftyp MP4_ID('f', 't', 'y', 'p')
#define MP4_gnre MP4_ID('g', 'n', 'r', 'e')
#define MP4_hdlr MP4_ID('h', 'd', 'l', 'r')
#define MP4_ilst MP4_ID('i', 'l', 's', 't')
#define MP4_M4A MP4_ID('M', '4', 'A', ' ')
#define MP4_M4B MP4_ID('M', '4', 'B', ' ')
#define MP4_mdat MP4_ID('m', 'd', 'a', 't')
#define MP4_mdia MP4_ID('m', 'd', 'i', 'a')
#define MP4_mdir MP4_ID('m', 'd', 'i', 'r')
#define MP4_meta MP4_ID('m', 'e', 't', 'a')
#define MP4_minf MP4_ID('m', 'i', 'n', 'f')
#define MP4_moov MP4_ID('m', 'o', 'o', 'v')
#define MP4_mp4a MP4_ID('m', 'p', '4', 'a')
#define MP4_mp42 MP4_ID('m', 'p', '4', '2')
#define MP4_qt MP4_ID('q', 't', ' ', ' ')
#define MP4_soun MP4_ID('s', 'o', 'u', 'n')
#define MP4_stbl MP4_ID('s', 't', 'b', 'l')
#define MP4_stsd MP4_ID('s', 't', 's', 'd')
#define MP4_stts MP4_ID('s', 't', 't', 's')
#define MP4_trak MP4_ID('t', 'r', 'a', 'k')
#define MP4_trkn MP4_ID('t', 'r', 'k', 'n')
#define MP4_udta MP4_ID('u', 'd', 't', 'a')
#define MP4_extra MP4_ID('-', '-', '-', '-')
/* Read the tag data from an MP4 file, storing up to buffer_size bytes in
* buffer.
*/
static unsigned long read_mp4_tag(int fd, unsigned int size_left, char* buffer,
unsigned int buffer_left)
{
unsigned int bytes_read = 0;
if (buffer_left == 0)
{
lseek(fd, size_left, SEEK_CUR); /* Skip everything */
}
else
{
/* Skip the data tag header - maybe we should parse it properly? */
lseek(fd, 16, SEEK_CUR);
size_left -= 16;
if (size_left > buffer_left)
{
read(fd, buffer, buffer_left);
lseek(fd, size_left - buffer_left, SEEK_CUR);
bytes_read = buffer_left;
}
else
{
read(fd, buffer, size_left);
bytes_read = size_left;
}
}
return bytes_read;
}
/* Read a string tag from an MP4 file */
static unsigned int read_mp4_tag_string(int fd, int size_left, char** buffer,
unsigned int* buffer_left, char** dest)
{
unsigned int bytes_read = read_mp4_tag(fd, size_left, *buffer,
*buffer_left > 0 ? *buffer_left - 1 : 0);
unsigned int length = 0;
if (bytes_read)
{
(*buffer)[bytes_read] = 0;
*dest = *buffer;
length = strlen(*buffer) + 1;
*buffer_left -= length;
*buffer += length;
}
else
{
*dest = NULL;
}
return length;
}
static unsigned int read_mp4_atom(int fd, unsigned int* size,
unsigned int* type, unsigned int size_left)
{
read_uint32be(fd, size);
read_uint32be(fd, type);
if (*size == 1)
{
/* FAT32 doesn't support files this big, so something seems to
* be wrong. (64-bit sizes should only be used when required.)
*/
errno = EFBIG;
*type = 0;
return 0;
}
if (*size > 0)
{
if (*size > size_left)
{
size_left = 0;
}
else
{
size_left -= *size;
}
*size -= 8;
}
else
{
*size = size_left;
size_left = 0;
}
return size_left;
}
static unsigned int read_mp4_length(int fd, unsigned int* size)
{
unsigned int length = 0;
int bytes = 0;
unsigned char c;
do
{
read(fd, &c, 1);
bytes++;
(*size)--;
length = (length << 7) | (c & 0x7F);
}
while ((c & 0x80) && (bytes < 4) && (*size > 0));
return length;
}
static bool read_mp4_esds(int fd, struct mp3entry* id3,
unsigned int* size)
{
unsigned char buf[8];
bool sbr = false;
lseek(fd, 4, SEEK_CUR); /* Version and flags. */
read(fd, buf, 1); /* Verify ES_DescrTag. */
*size -= 5;
if (*buf == 3)
{
/* read length */
if (read_mp4_length(fd, size) < 20)
{
return sbr;
}
lseek(fd, 3, SEEK_CUR);
*size -= 3;
}
else
{
lseek(fd, 2, SEEK_CUR);
*size -= 2;
}
read(fd, buf, 1); /* Verify DecoderConfigDescrTab. */
*size -= 1;
if (*buf != 4)
{
return sbr;
}
if (read_mp4_length(fd, size) < 13)
{
return sbr;
}
lseek(fd, 13, SEEK_CUR); /* Skip audio type, bit rates, etc. */
read(fd, buf, 1);
*size -= 14;
if (*buf != 5) /* Verify DecSpecificInfoTag. */
{
return sbr;
}
{
static const int sample_rates[] =
{
96000, 88200, 64000, 48000, 44100, 32000,
24000, 22050, 16000, 12000, 11025, 8000
};
unsigned long bits;
unsigned int length;
unsigned int index;
unsigned int type;
/* Read the (leading part of the) decoder config. */
length = read_mp4_length(fd, size);
length = MIN(length, *size);
length = MIN(length, sizeof(buf));
memset(buf, 0, sizeof(buf));
read(fd, buf, length);
*size -= length;
/* Maybe time to write a simple read_bits function... */
/* Decoder config format:
* Object type - 5 bits
* Frequency index - 4 bits
* Channel configuration - 4 bits
*/
bits = get_long_be(buf);
type = bits >> 27; /* Object type - 5 bits */
index = (bits >> 23) & 0xf; /* Frequency index - 4 bits */
if (index < (sizeof(sample_rates) / sizeof(*sample_rates)))
{
id3->frequency = sample_rates[index];
}
if (type == 5)
{
DEBUGF("MP4: SBR\n");
unsigned int old_index = index;
sbr = true;
index = (bits >> 15) & 0xf; /* Frequency index - 4 bits */
if (index == 15)
{
/* 17 bits read so far... */
bits = get_long_be(&buf[2]);
id3->frequency = (bits >> 7) & 0x00ffffff;
}
else if (index < (sizeof(sample_rates) / sizeof(*sample_rates)))
{
id3->frequency = sample_rates[index];
}
if (old_index == index)
{
/* Downsampled SBR */
id3->frequency *= 2;
}
}
/* Skip 13 bits from above, plus 3 bits, then read 11 bits */
else if ((length >= 4) && (((bits >> 5) & 0x7ff) == 0x2b7))
{
/* extensionAudioObjectType */
DEBUGF("MP4: extensionAudioType\n");
type = bits & 0x1f; /* Object type - 5 bits*/
bits = get_long_be(&buf[4]);
if (type == 5)
{
sbr = bits >> 31;
if (sbr)
{
unsigned int old_index = index;
/* 1 bit read so far */
index = (bits >> 27) & 0xf; /* Frequency index - 4 bits */
if (index == 15)
{
/* 5 bits read so far */
id3->frequency = (bits >> 3) & 0x00ffffff;
}
else if (index < (sizeof(sample_rates) / sizeof(*sample_rates)))
{
id3->frequency = sample_rates[index];
}
if (old_index == index)
{
/* Downsampled SBR */
id3->frequency *= 2;
}
}
}
}
if (!sbr && (id3->frequency <= 24000) && (length <= 2))
{
/* Double the frequency for low-frequency files without a "long"
* DecSpecificConfig header. The file may or may not contain SBR,
* but here we guess it does if the header is short. This can
* fail on some files, but it's the best we can do, short of
* decoding (parts of) the file.
*/
id3->frequency *= 2;
}
}
return sbr;
}
static bool read_mp4_tags(int fd, struct mp3entry* id3,
unsigned int size_left)
{
unsigned int size;
unsigned int type;
unsigned int buffer_left = sizeof(id3->id3v2buf) + sizeof(id3->id3v1buf);
char* buffer = id3->id3v2buf;
bool cwrt = false;
do
{
size_left = read_mp4_atom(fd, &size, &type, size_left);
/* DEBUGF("Tag atom: '%c%c%c%c' (%d bytes left)\n", type >> 24 & 0xff,
type >> 16 & 0xff, type >> 8 & 0xff, type & 0xff, size); */
switch (type)
{
case MP4_cnam:
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->title);
break;
case MP4_cART:
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->artist);
break;
case MP4_aART:
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->albumartist);
break;
case MP4_cgrp:
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->grouping);
break;
case MP4_calb:
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->album);
break;
case MP4_cwrt:
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->composer);
cwrt = false;
break;
case MP4_ccmt:
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->comment);
break;
case MP4_cday:
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->year_string);
/* Try to parse it as a year, for the benefit of the database.
*/
if(id3->year_string)
{
id3->year = atoi(id3->year_string);
if (id3->year < 1900)
{
id3->year = 0;
}
}
else
id3->year = 0;
break;
case MP4_gnre:
{
unsigned short genre;
read_mp4_tag(fd, size, (char*) &genre, sizeof(genre));
id3->genre_string = id3_get_num_genre(betoh16(genre) - 1);
}
break;
case MP4_cgen:
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->genre_string);
break;
case MP4_disk:
{
unsigned short n[2];
read_mp4_tag(fd, size, (char*) &n, sizeof(n));
id3->discnum = betoh16(n[1]);
}
break;
case MP4_trkn:
{
unsigned short n[2];
read_mp4_tag(fd, size, (char*) &n, sizeof(n));
id3->tracknum = betoh16(n[1]);
}
break;
case MP4_extra:
{
char tag_name[TAG_NAME_LENGTH];
unsigned int sub_size;
/* "mean" atom */
read_uint32be(fd, &sub_size);
size -= sub_size;
lseek(fd, sub_size - 4, SEEK_CUR);
/* "name" atom */
read_uint32be(fd, &sub_size);
size -= sub_size;
lseek(fd, 8, SEEK_CUR);
sub_size -= 12;
if (sub_size > sizeof(tag_name) - 1)
{
read(fd, tag_name, sizeof(tag_name) - 1);
lseek(fd, sub_size - (sizeof(tag_name) - 1), SEEK_CUR);
tag_name[sizeof(tag_name) - 1] = 0;
}
else
{
read(fd, tag_name, sub_size);
tag_name[sub_size] = 0;
}
if ((strcasecmp(tag_name, "composer") == 0) && !cwrt)
{
read_mp4_tag_string(fd, size, &buffer, &buffer_left,
&id3->composer);
}
else if (strcasecmp(tag_name, "iTunSMPB") == 0)
{
char value[TAG_VALUE_LENGTH];
char* value_p = value;
char* any;
unsigned int length = sizeof(value);
read_mp4_tag_string(fd, size, &value_p, &length, &any);
id3->lead_trim = get_itunes_int32(value, 1);
id3->tail_trim = get_itunes_int32(value, 2);
DEBUGF("AAC: lead_trim %d, tail_trim %d\n",
id3->lead_trim, id3->tail_trim);
}
else
{
char* any;
unsigned int length = read_mp4_tag_string(fd, size,
&buffer, &buffer_left, &any);
if (length > 0)
{
/* Re-use the read buffer as the dest buffer... */
buffer -= length;
buffer_left += length;
if (parse_replaygain(tag_name, buffer, id3,
buffer, buffer_left) > 0)
{
/* Data used, keep it. */
buffer += length;
buffer_left -= length;
}
}
}
}
break;
default:
lseek(fd, size, SEEK_CUR);
break;
}
}
while ((size_left > 0) && (errno == 0));
return true;
}
static bool read_mp4_container(int fd, struct mp3entry* id3,
unsigned int size_left)
{
unsigned int size;
unsigned int type;
unsigned int handler = 0;
bool rc = true;
do
{
size_left = read_mp4_atom(fd, &size, &type, size_left);
/* DEBUGF("Atom: '%c%c%c%c' (0x%08x, %d bytes left)\n",
(type >> 24) & 0xff, (type >> 16) & 0xff, (type >> 8) & 0xff,
type & 0xff, type, size); */
switch (type)
{
case MP4_ftyp:
{
unsigned int id;
read_uint32be(fd, &id);
size -= 4;
if ((id != MP4_M4A) && (id != MP4_M4B) && (id != MP4_mp42)
&& (id != MP4_qt) && (id != MP4_3gp6))
{
DEBUGF("Unknown MP4 file type: '%c%c%c%c'\n",
id >> 24 & 0xff, id >> 16 & 0xff, id >> 8 & 0xff,
id & 0xff);
return false;
}
}
break;
case MP4_meta:
lseek(fd, 4, SEEK_CUR); /* Skip version */
size -= 4;
/* Fall through */
case MP4_moov:
case MP4_udta:
case MP4_mdia:
case MP4_stbl:
case MP4_trak:
rc = read_mp4_container(fd, id3, size);
size = 0;
break;
case MP4_ilst:
if (handler == MP4_mdir)
{
rc = read_mp4_tags(fd, id3, size);
size = 0;
}
break;
case MP4_minf:
if (handler == MP4_soun)
{
rc = read_mp4_container(fd, id3, size);
size = 0;
}
break;
case MP4_stsd:
lseek(fd, 8, SEEK_CUR);
size -= 8;
rc = read_mp4_container(fd, id3, size);
size = 0;
break;
case MP4_hdlr:
lseek(fd, 8, SEEK_CUR);
read_uint32be(fd, &handler);
size -= 12;
/* DEBUGF(" Handler '%c%c%c%c'\n", handler >> 24 & 0xff,
handler >> 16 & 0xff, handler >> 8 & 0xff,handler & 0xff); */
break;
case MP4_stts:
{
unsigned int entries;
unsigned int i;
lseek(fd, 4, SEEK_CUR);
read_uint32be(fd, &entries);
id3->samples = 0;
for (i = 0; i < entries; i++)
{
unsigned int n;
unsigned int l;
read_uint32be(fd, &n);
read_uint32be(fd, &l);
id3->samples += n * l;
}
size = 0;
}
break;
case MP4_mp4a:
case MP4_alac:
{
unsigned int frequency;
id3->codectype = (type == MP4_mp4a) ? AFMT_AAC : AFMT_ALAC;
lseek(fd, 22, SEEK_CUR);
read_uint32be(fd, &frequency);
size -= 26;
id3->frequency = frequency;
if (type == MP4_mp4a)
{
unsigned int subsize;
unsigned int subtype;
/* Get frequency from the decoder info tag, if possible. */
lseek(fd, 2, SEEK_CUR);
/* The esds atom is a part of the mp4a atom, so ignore
* the returned size (it's already accounted for).
*/
read_mp4_atom(fd, &subsize, &subtype, size);
size -= 10;
if (subtype == MP4_esds)
{
read_mp4_esds(fd, id3, &size);
}
}
}
break;
case MP4_mdat:
id3->filesize = size;
break;
default:
break;
}
lseek(fd, size, SEEK_CUR);
}
while (rc && (size_left > 0) && (errno == 0) && (id3->filesize == 0));
/* Break on non-zero filesize, since Rockbox currently doesn't support
* metadata after the mdat atom (which sets the filesize field).
*/
return rc;
}
bool get_mp4_metadata(int fd, struct mp3entry* id3)
{
id3->codectype = AFMT_UNKNOWN;
id3->filesize = 0;
errno = 0;
if (read_mp4_container(fd, id3, filesize(fd)) && (errno == 0)
&& (id3->samples > 0) && (id3->frequency > 0)
&& (id3->filesize > 0))
{
if (id3->codectype == AFMT_UNKNOWN)
{
logf("Not an ALAC or AAC file");
return false;
}
id3->length = ((int64_t) id3->samples * 1000) / id3->frequency;
if (id3->length <= 0)
{
logf("mp4 length invalid!");
return false;
}
id3->bitrate = ((int64_t) id3->filesize * 8) / id3->length;
DEBUGF("MP4 bitrate %d, frequency %ld Hz, length %ld ms\n",
id3->bitrate, id3->frequency, id3->length);
}
else
{
logf("MP4 metadata error");
DEBUGF("MP4 metadata error. errno %d, frequency %ld, filesize %ld\n",
errno, id3->frequency, id3->filesize);
return false;
}
return true;
}