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MP3: skip ID3V2 metadata

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This was one reason that the "bartlebeats" mp3s would not play.
This commit is contained in:
Jeff Epler 2019-12-13 14:07:00 -06:00
parent a854a76819
commit bf9b7e7ece
1 changed files with 35 additions and 0 deletions
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35
shared-module/audiomp3/MP3File.c
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@ -88,6 +88,39 @@ STATIC bool mp3file_update_inbuf(audiomp3_mp3file_obj_t* self) {
#define BYTES_LEFT(self) (self->inbuf_length - self->inbuf_offset)
#define CONSUME(self, n) (self->inbuf_offset += n)
// http://id3.org/d3v2.3.0
// http://id3.org/id3v2.3.0
STATIC void mp3file_skip_id3v2(audiomp3_mp3file_obj_t* self) {
mp3file_update_inbuf(self);
if (BYTES_LEFT(self) < 10) {
return;
}
uint8_t *data = READ_PTR(self);
if (!(
data[0] == 'I' &&
data[1] == 'D' &&
data[2] == '3' &&
data[3] != 0xff &&
data[4] != 0xff &&
(data[5] & 0x1f) == 0 &&
(data[6] & 0x80) == 0 &&
(data[7] & 0x80) == 0 &&
(data[8] & 0x80) == 0 &&
(data[9] & 0x80) == 0)) {
return;
}
uint32_t size = (data[6] << 21) | (data[7] << 14) | (data[8] << 7) | (data[9]);
size += 10; // size excludes the "header" (but not the "extended header")
// First, deduct from size whatever is left in buffer
uint32_t to_consume = MIN(size, BYTES_LEFT(self));
CONSUME(self, to_consume);
size -= to_consume;
// Next, seek in the file after the header
f_lseek(&self->file->fp, f_tell(&self->file->fp) + size);
return;
}
/* If a sync word can be found, advance to it and return true. Otherwise,
* return false.
*/
@ -223,6 +256,7 @@ void audiomp3_mp3file_reset_buffer(audiomp3_mp3file_obj_t* self,
self->eof = 0;
self->other_channel = -1;
mp3file_update_inbuf(self);
mp3file_skip_id3v2(self);
mp3file_find_sync_word(self);
}
@ -253,6 +287,7 @@ audioio_get_buffer_result_t audiomp3_mp3file_get_buffer(audiomp3_mp3file_obj_t*
self->buffer_index = !self->buffer_index;
int16_t *buffer = (int16_t *)(void *)self->buffers[self->buffer_index];
mp3file_skip_id3v2(self);
if (!mp3file_find_sync_word(self)) {
return self->eof ? GET_BUFFER_DONE : GET_BUFFER_ERROR;
}