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Better generation of Xing headers, now they contain the correct MPEG version and sample rate info.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@3567 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Linus Nielsen Feltzing 2003-04-19 01:59:23 +00:00
parent 1c32bd0f48
commit 7fdef57d57
4 changed files with 118 additions and 97 deletions
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130
apps/onplay.c
View file

@ -210,14 +210,15 @@ static const unsigned char empty_id3_header[] =
static bool vbr_fix(void)
{
unsigned char xingbuf[417];
unsigned char xingbuf[1500];
struct mp3entry entry;
int fd;
int rc;
int flen;
int num_frames;
int fpos;
int numbytes;
int framelen;
int unused_space;
if(mpeg_status()) {
splash(HZ*2, 0, true, str(LANG_VBRFIX_STOP_PLAY));
@ -250,26 +251,45 @@ static bool vbr_fix(void)
flen, xingupdate);
if(num_frames) {
create_xing_header(fd, entry.first_frame_offset,
flen, xingbuf, num_frames, xingupdate, true);
/* Note: We don't need to pass any values for mpeg_version and
sample_rate because they will be extracted from the mpeg stream */
framelen = create_xing_header(fd, entry.first_frame_offset,
flen, xingbuf, num_frames,
0, 0, xingupdate, true);
/* Try to fit the Xing header first in the stream. Replace the existing
Xing header if there is one, else see if there is room between the
VBR header if there is one, else see if there is room between the
ID3 tag and the first MP3 frame. */
if(entry.vbr_header_pos) {
/* Reuse existing Xing header */
fpos = entry.vbr_header_pos;
DEBUGF("Reusing Xing header at %d\n", fpos);
rc = lseek(fd, entry.vbr_header_pos, SEEK_SET);
if(entry.first_frame_offset - entry.id3v2len >=
(unsigned int)framelen) {
DEBUGF("Using existing space between ID3 and first frame\n");
/* Seek to the beginning of the unused space */
rc = lseek(fd, entry.id3v2len, SEEK_SET);
if(rc < 0) {
close(fd);
fileerror(rc);
return true;
}
unused_space =
entry.first_frame_offset - entry.id3v2len - framelen;
rc = write(fd, xingbuf, 417);
/* Fill the unused space with 0's (using the MP3 buffer)
and write it to the file */
if(unused_space)
{
memset(mp3buf, 0, unused_space);
rc = write(fd, mp3buf, unused_space);
if(rc < 0) {
close(fd);
fileerror(rc);
return true;
}
}
/* Then write the Xing header */
rc = write(fd, xingbuf, framelen);
if(rc < 0) {
close(fd);
fileerror(rc);
@ -278,61 +298,41 @@ static bool vbr_fix(void)
close(fd);
} else {
/* Any room between ID3 tag and first MP3 frame? */
if(entry.first_frame_offset - entry.id3v2len > 417) {
DEBUGF("Using existing space between ID3 and first frame\n");
rc = lseek(fd, entry.first_frame_offset - 417, SEEK_SET);
if(rc < 0) {
close(fd);
fileerror(rc);
return true;
}
rc = write(fd, xingbuf, 417);
if(rc < 0) {
close(fd);
fileerror(rc);
return true;
}
close(fd);
/* If not, insert some space. If there is an ID3 tag in the
file we only insert just enough to squeeze the Xing header
in. If not, we insert an additional empty ID3 tag of 4K. */
close(fd);
/* Nasty trick alert! The insert_data_in_file() function
uses the MP3 buffer when copying the data. We assume
that the ID3 tag isn't longer than 1MB so the xing
buffer won't be overwritten. */
if(entry.first_frame_offset) {
DEBUGF("Inserting %d bytes\n", framelen);
numbytes = framelen;
} else {
/* If not, insert some space. If there is an ID3 tag in the
file we only insert just enough to squeeze the Xing header
in. If not, we insert an additional empty ID3 tag of 4K. */
close(fd);
/* Nasty trick alert! The insert_data_in_file() function
uses the MP3 buffer when copying the data. We assume
that the ID3 tag isn't longer than 1MB so the xing
buffer won't be overwritten. */
if(entry.first_frame_offset) {
DEBUGF("Inserting 417 bytes\n");
numbytes = 417;
} else {
DEBUGF("Inserting 4096+417 bytes\n");
numbytes = 4096 + 417;
memset(mp3buf + 0x100000, 0, numbytes);
/* Insert the ID3 header */
memcpy(mp3buf + 0x100000, empty_id3_header,
sizeof(empty_id3_header));
}
/* Copy the Xing header */
memcpy(mp3buf + 0x100000 + numbytes - 417, xingbuf, 417);
DEBUGF("Inserting 4096+%d bytes\n", framelen);
numbytes = 4096 + framelen;
rc = insert_data_in_file(selected_file,
entry.first_frame_offset,
mp3buf + 0x100000, numbytes);
memset(mp3buf + 0x100000, 0, numbytes);
if(rc < 0) {
fileerror(rc);
return true;
}
/* Insert the ID3 header */
memcpy(mp3buf + 0x100000, empty_id3_header,
sizeof(empty_id3_header));
}
/* Copy the Xing header */
memcpy(mp3buf + 0x100000 + numbytes - framelen, xingbuf, framelen);
rc = insert_data_in_file(selected_file,
entry.first_frame_offset,
mp3buf + 0x100000, numbytes);
if(rc < 0) {
fileerror(rc);
return true;
}
}

1
firmware/export/mp3data.h
View file

@ -61,6 +61,7 @@ int count_mp3_frames(int fd, int startpos, int filesize,
void (*progressfunc)(int));
int create_xing_header(int fd, int startpos, int filesize,
unsigned char *buf, int num_frames,
int mpeg_version, int sample_rate,
void (*progressfunc)(int), bool generate_toc);
#endif

41
firmware/mp3data.c
View file

@ -35,7 +35,7 @@
#include "mp3data.h"
#include "file.h"
#undef DEBUG_VERBOSE
#define DEBUG_VERBOSE
#define BYTES2INT(b1,b2,b3,b4) (((b1 & 0xFF) << (3*8)) | \
((b2 & 0xFF) << (2*8)) | \
@ -530,9 +530,10 @@ int get_mp3file_info(int fd, struct mp3info *info)
return bytecount;
}
/* This is an MP3 header, 128kbit/s, 44.1kHz, with silence */
/* This is an MP3 header, 128kbit/s, with silence
MPEG version and sample frequency are not set */
static const unsigned char xing_frame_header[] = {
0xff, 0xfa, 0x90, 0x64, 0x86, 0x1f
0xff, 0xe2, 0x90, 0x64, 0x86, 0x1f
};
static const char cooltext[] = "Rockbox rocks";
@ -601,11 +602,15 @@ int count_mp3_frames(int fd, int startpos, int filesize,
}
}
/* Note: mpeg_version and sample_rate are 2-bit values, as specified by the
MPEG frame standard. See the tables above. */
int create_xing_header(int fd, int startpos, int filesize,
unsigned char *buf, int num_frames,
int mpeg_version, int sample_rate,
void (*progressfunc)(int), bool generate_toc)
{
unsigned long header = 0;
unsigned long saved_header;
struct mp3info info;
int pos, last_pos;
int i, j;
@ -618,9 +623,9 @@ int create_xing_header(int fd, int startpos, int filesize,
DEBUGF("create_xing_header()\n");
/* Create the frame header */
memset(buf, 0, 417);
memset(buf, 0, 1500);
memcpy(buf, xing_frame_header, 6);
lseek(fd, startpos, SEEK_SET);
buf_init();
@ -664,6 +669,10 @@ int create_xing_header(int fd, int startpos, int filesize,
buf_seek(fd, info.frame_size-4);
filepos += info.frame_size;
}
/* Save one header for later use */
if(i == 1)
saved_header = header;
if(progressfunc)
{
@ -684,6 +693,26 @@ int create_xing_header(int fd, int startpos, int filesize,
memcpy(buf + index + 100, cooltext, sizeof(cooltext));
/* We must fill in the correct sample rate and mpeg version. If the TOC
should be generated, we take that data from the actual stream. If not,
we use the supplied parameters. */
if(generate_toc)
{
saved_header &= (VERSION_MASK | SAMPLERATE_MASK);
buf[1] |= (saved_header >> 16) & 0xff;
buf[2] |= (saved_header >> 8) & 0xff;
}
else
{
buf[1] |= mpeg_version << 3;
buf[2] |= sample_rate << 2;
}
/* Now get the length of the newly created frame */
header = BYTES2INT(buf[0], buf[1], buf[2], buf[3]);
mp3headerinfo(&info, header);
#ifdef DEBUG
for(i = 0;i < 417;i++)
{
@ -694,5 +723,5 @@ int create_xing_header(int fd, int startpos, int filesize,
}
#endif
return 0;
return info.frame_size;
}

43
firmware/mpeg.c
View file

@ -489,7 +489,8 @@ unsigned long record_start_time; /* Value of current_tick when recording
was started */
static bool saving; /* We are saving the buffer to disk */
static char recording_filename[MAX_PATH];
static int rec_frequency_index; /* For create_xing_header() calls */
static int rec_version_index; /* For create_xing_header() calls */
#endif
static int mpeg_file;
@ -1010,13 +1011,6 @@ void IRQ3(void)
dma_tick();
else
postpone_dma_tick();
#if 0
if(mpeg_mode == MPEG_ENCODER)
/* Shut off if recording is stopped */
if(!is_recording)
demand_irq_enable(false);
#endif
}
#endif
@ -1271,6 +1265,7 @@ static void mpeg_thread(void)
#ifdef HAVE_MAS3587F
int amount_to_save;
int writelen;
int framelen;
#endif
is_playing = false;
@ -1734,15 +1729,6 @@ static void mpeg_thread(void)
DEBUGF("R\n");
t1 = current_tick;
len = read(mpeg_file, mp3buf+mp3buf_write, amount_to_read);
#if 0
if(id3tags[tag_read_idx]->id3.vbr)
/* Average bitrate * 1.5 */
recalculate_watermark(
(id3tags[tag_read_idx]->id3.bitrate * 3) / 2);
else
recalculate_watermark(
id3tags[tag_read_idx]->id3.bitrate);
#endif
if(len > 0)
{
t2 = current_tick;
@ -1854,10 +1840,10 @@ static void mpeg_thread(void)
DEBUGF("Recording...\n");
reset_mp3_buffer();
/* Advance the write pointer 4096+417 bytes to make
/* Advance the write pointer 4096+1500 bytes to make
room for an ID3 tag plus a VBR header */
mp3buf_write = 4096+417;
memset(mp3buf, 0, 4096+417);
mp3buf_write = 4096+1500;
memset(mp3buf, 0, 4096+1500);
/* Insert the ID3 header */
memcpy(mp3buf, empty_id3_header, sizeof(empty_id3_header));
@ -1898,12 +1884,14 @@ static void mpeg_thread(void)
if(num_recorded_frames == 0x7ffff)
num_recorded_frames = 0;
create_xing_header(mpeg_file, 0, num_rec_bytes,
mp3buf, num_recorded_frames, NULL,
false);
framelen = create_xing_header(mpeg_file, 0, num_rec_bytes,
mp3buf, num_recorded_frames,
rec_version_index,
rec_frequency_index,
NULL, false);
lseek(mpeg_file, 4096, SEEK_SET);
write(mpeg_file, mp3buf, 417);
lseek(mpeg_file, 4096+1500-framelen, SEEK_SET);
write(mpeg_file, mp3buf, framelen);
close(mpeg_file);
mpeg_file = -1;
@ -2841,9 +2829,12 @@ void mpeg_set_recording_options(int frequency, int quality,
unsigned long val;
is_mpeg1 = (frequency < 3)?true:false;
rec_version_index = is_mpeg1?3:2;
rec_frequency_index = frequency % 3;
val = (quality << 17) |
((frequency % 3) << 10) |
(rec_frequency_index << 10) |
((is_mpeg1?1:0) << 9) |
(1 << 8) | /* CRC on */
(((channel_mode * 2 + 1) & 3) << 6) |