diff options
author | Marcoen Hirschberg <marcoen@gmail.com> | 2007-06-16 22:23:07 +0000 |
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committer | Marcoen Hirschberg <marcoen@gmail.com> | 2007-06-16 22:23:07 +0000 |
commit | 9e0dfa1a533206200d2fcc87113417d8676e8fd7 (patch) | |
tree | 7e87671501300d002d81a24b408fa34ed90fe330 /apps/metadata/vorbis.c | |
parent | 7420d5ae5c0b733018cedc3a1eef40b2112ff77f (diff) |
move the speex and vorbis ogg parsers together in ogg.c
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13642 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/metadata/vorbis.c')
-rw-r--r-- | apps/metadata/vorbis.c | 212 |
1 files changed, 0 insertions, 212 deletions
diff --git a/apps/metadata/vorbis.c b/apps/metadata/vorbis.c index 5112615e47..a93d271ad0 100644 --- a/apps/metadata/vorbis.c +++ b/apps/metadata/vorbis.c @@ -116,215 +116,3 @@ bool read_vorbis_tags(int fd, struct mp3entry *id3, return true; } - -/* A simple parser to read vital metadata from an Ogg Vorbis file. - * Calls get_speex_metadata if a speex file is identified. Returns - * false if metadata needed by the Vorbis codec couldn't be read. - */ -bool get_vorbis_metadata(int fd, struct mp3entry* id3) -{ - /* An Ogg File is split into pages, each starting with the string - * "OggS". Each page has a timestamp (in PCM samples) referred to as - * the "granule position". - * - * An Ogg Vorbis has the following structure: - * 1) Identification header (containing samplerate, numchannels, etc) - * 2) Comment header - containing the Vorbis Comments - * 3) Setup header - containing codec setup information - * 4) Many audio packets... - */ - - /* Use the path name of the id3 structure as a temporary buffer. */ - unsigned char* buf = (unsigned char *)id3->path; - long comment_size; - long remaining = 0; - long last_serial = 0; - long serial, r; - int segments; - int i; - bool eof = false; - - if ((lseek(fd, 0, SEEK_SET) < 0) || (read(fd, buf, 58) < 4)) - { - return false; - } - - if ((memcmp(buf, "OggS", 4) != 0) || (memcmp(&buf[29], "vorbis", 6) != 0)) - { - if ((memcmp(buf, "OggS", 4) != 0) || (memcmp(&buf[28], "Speex", 5) != 0)) - { - return false; - } - else - { - id3->codectype = AFMT_SPEEX; - return get_speex_metadata(fd, id3); - } - } - - /* We need to ensure the serial number from this page is the same as the - * one from the last page (since we only support a single bitstream). - */ - serial = get_long_le(&buf[14]); - id3->frequency = get_long_le(&buf[40]); - id3->filesize = filesize(fd); - - /* Comments are in second Ogg page */ - if (lseek(fd, 58, SEEK_SET) < 0) - { - return false; - } - - /* Minimum header length for Ogg pages is 27. */ - if (read(fd, buf, 27) < 27) - { - return false; - } - - if (memcmp(buf, "OggS", 4) !=0 ) - { - return false; - } - - segments = buf[26]; - - /* read in segment table */ - if (read(fd, buf, segments) < segments) - { - return false; - } - - /* The second packet in a vorbis stream is the comment packet. It *may* - * extend beyond the second page, but usually does not. Here we find the - * length of the comment packet (or the rest of the page if the comment - * packet extends to the third page). - */ - for (i = 0; i < segments; i++) - { - remaining += buf[i]; - - /* The last segment of a packet is always < 255 bytes */ - if (buf[i] < 255) - { - break; - } - } - - /* Now read in packet header (type and id string) */ - if (read(fd, buf, 7) < 7) - { - return false; - } - - comment_size = remaining; - remaining -= 7; - - /* The first byte of a packet is the packet type; comment packets are - * type 3. - */ - if ((buf[0] != 3) || (memcmp(buf + 1, "vorbis", 6) !=0)) - { - return false; - } - - /* Failure to read the tags isn't fatal. */ - read_vorbis_tags(fd, id3, remaining); - - /* We now need to search for the last page in the file - identified by - * by ('O','g','g','S',0) and retrieve totalsamples. - */ - - /* A page is always < 64 kB */ - if (lseek(fd, -(MIN(64 * 1024, id3->filesize)), SEEK_END) < 0) - { - return false; - } - - remaining = 0; - - while (!eof) - { - r = read(fd, &buf[remaining], MAX_PATH - remaining); - - if (r <= 0) - { - eof = true; - } - else - { - remaining += r; - } - - /* Inefficient (but simple) search */ - i = 0; - - while (i < (remaining - 3)) - { - if ((buf[i] == 'O') && (memcmp(&buf[i], "OggS", 4) == 0)) - { - if (i < (remaining - 17)) - { - /* Note that this only reads the low 32 bits of a - * 64 bit value. - */ - id3->samples = get_long_le(&buf[i + 6]); - last_serial = get_long_le(&buf[i + 14]); - - /* If this page is very small the beginning of the next - * header could be in buffer. Jump near end of this header - * and continue */ - i += 27; - } - else - { - break; - } - } - else - { - i++; - } - } - - if (i < remaining) - { - /* Move the remaining bytes to start of buffer. - * Reuse var 'segments' as it is no longer needed */ - segments = 0; - while (i < remaining) - { - buf[segments++] = buf[i++]; - } - remaining = segments; - } - else - { - /* Discard the rest of the buffer */ - remaining = 0; - } - } - - /* This file has mutiple vorbis bitstreams (or is corrupt). */ - /* FIXME we should display an error here. */ - if (serial != last_serial) - { - logf("serialno mismatch"); - logf("%ld", serial); - logf("%ld", last_serial); - return false; - } - - id3->length = ((int64_t) id3->samples * 1000) / id3->frequency; - - if (id3->length <= 0) - { - logf("ogg length invalid!"); - return false; - } - - id3->bitrate = (((int64_t) id3->filesize - comment_size) * 8) / id3->length; - id3->vbr = true; - - return true; -} - |