diff options
Diffstat (limited to 'apps/mp3data.c')
| -rw-r--r-- | apps/mp3data.c | 299 |
1 files changed, 141 insertions, 158 deletions
diff --git a/apps/mp3data.c b/apps/mp3data.c index f5ef122801..35b4608396 100644 --- a/apps/mp3data.c +++ b/apps/mp3data.c @@ -349,32 +349,135 @@ unsigned long mem_find_next_frame(int startpos, long *offset, long max_offset, } #endif -int get_mp3file_info(int fd, struct mp3info *info) +/* Extract information from a 'Xing' or 'Info' header. */ +static void get_xing_info(struct mp3info *info, unsigned char *buf) { - unsigned char frame[1800]; - unsigned char *vbrheader; - unsigned long header; - long bytecount; - int num_offsets; - int i; - long offset; - int j; - long tmp; + int i = 8; + + /* Is it a VBR file? */ + info->is_vbr = !memcmp(buf, "Xing", 4); - header = find_next_frame(fd, &bytecount, 0x20000, 0); - /* Quit if we haven't found a valid header within 128K */ + if (buf[7] & VBR_FRAMES_FLAG) /* Is the frame count there? */ + { + info->frame_count = bytes2int(buf[i], buf[i+1], buf[i+2], buf[i+3]); + if (info->frame_count <= ULONG_MAX / info->ft_num) + info->file_time = info->frame_count * info->ft_num / info->ft_den; + else + info->file_time = info->frame_count / info->ft_den * info->ft_num; + i += 4; + } + + if (buf[7] & VBR_BYTES_FLAG) /* Is byte count there? */ + { + info->byte_count = bytes2int(buf[i], buf[i+1], buf[i+2], buf[i+3]); + i += 4; + } + + if (info->file_time && info->byte_count) + { + if (info->byte_count <= (ULONG_MAX/8)) + info->bitrate = info->byte_count * 8 / info->file_time; + else + info->bitrate = info->byte_count / (info->file_time >> 3); + } + + if (buf[7] & VBR_TOC_FLAG) /* Is table-of-contents there? */ + { + info->has_toc = true; + memcpy( info->toc, buf+i, 100 ); + i += 100; + } + if (buf[7] & VBR_QUALITY_FLAG) + { + /* We don't care about this, but need to skip it */ + i += 4; + } +#if CONFIG_CODEC==SWCODEC + i += 21; + info->enc_delay = ((int)buf[i ] << 4) | (buf[i+1] >> 4); + info->enc_padding = ((int)buf[i+1] << 8) | buf[i+2]; + /* TODO: This sanity checking is rather silly, seeing as how the LAME + header contains a CRC field that can be used to verify integrity. */ + if (!(info->enc_delay >= 0 && info->enc_delay <= 2880 && + info->enc_padding >= 0 && info->enc_padding <= 2*1152)) + { + /* Invalid data */ + info->enc_delay = -1; + info->enc_padding = -1; + } +#endif +} + +/* Extract information from a 'VBRI' header. */ +static void get_vbri_info(struct mp3info *info, unsigned char *buf) +{ + int i, num_offsets, offset = 0; + + info->is_vbr = true; /* Yes, it is a FhG VBR file */ + info->has_toc = false; /* We don't parse the TOC (yet) */ + + info->byte_count = bytes2int(buf[10], buf[11], buf[12], buf[13]); + info->frame_count = bytes2int(buf[14], buf[15], buf[16], buf[17]); + if (info->frame_count <= ULONG_MAX / info->ft_num) + info->file_time = info->frame_count * info->ft_num / info->ft_den; + else + info->file_time = info->frame_count / info->ft_den * info->ft_num; + + if (info->byte_count <= (ULONG_MAX/8)) + info->bitrate = info->byte_count * 8 / info->file_time; + else + info->bitrate = info->byte_count / (info->file_time >> 3); + + /* We don't parse the TOC, since we don't yet know how to (FIXME) */ + num_offsets = bytes2int(0, 0, buf[18], buf[19]); + VDEBUGF("Frame size (%dkpbs): %d bytes (0x%x)\n", + info->bitrate, info->frame_size, info->frame_size); + VDEBUGF("Frame count: %lx\n", info->frame_count); + VDEBUGF("Byte count: %lx\n", info->byte_count); + VDEBUGF("Offsets: %d\n", num_offsets); + VDEBUGF("Frames/entry: %ld\n", + bytes2int(0, 0, buf[24], buf[25])); + + for(i = 0; i < num_offsets; i++) + { + offset += bytes2int(0, 0, buf[26+i*2], buf[27+i*2]);; + VDEBUGF("%03d: %lx\n", i, offset - bytecount,); + } +} + +/* Seek to next mpeg header and extract relevant information. */ +static int get_next_header_info(int fd, long *bytecount, struct mp3info *info) +{ + unsigned long header = find_next_frame(fd, bytecount, 0x20000, 0); if(header == 0) return -1; + if(!mp3headerinfo(info, header)) + return -2; + + return 0; +} + +int get_mp3file_info(int fd, struct mp3info *info) +{ + unsigned char frame[1800], *vbrheader; + long bytecount; + int result; + + /* Initialize info and frame */ memset(info, 0, sizeof(struct mp3info)); memset(frame, 0, sizeof(frame)); + #if CONFIG_CODEC==SWCODEC /* These two are needed for proper LAME gapless MP3 playback */ - info->enc_delay = -1; + info->enc_delay = -1; info->enc_padding = -1; #endif - if(!mp3headerinfo(info, header)) - return -2; + + /* Get the very first MPEG frame. */ + result = get_next_header_info(fd, &bytecount, info); + if(result) + return result; /* OK, we have found a frame. Let's see if it has a Xing header */ if (info->frame_size-4 >= (int)sizeof(frame)) @@ -386,170 +489,50 @@ int get_mp3file_info(int fd, struct mp3info *info) if(read(fd, frame, info->frame_size-4) < 0) return -3; - /* calculate position of VBR header */ - if ( info->version == MPEG_VERSION1 ) { + /* Calculate position of a possible VBR header */ + if (info->version == MPEG_VERSION1) { if (info->channel_mode == 3) /* mono */ vbrheader = frame + 17; else vbrheader = frame + 32; - } - else { + } else { if (info->channel_mode == 3) /* mono */ vbrheader = frame + 9; else vbrheader = frame + 17; } - if (!memcmp(vbrheader, "Xing", 4) - || !memcmp(vbrheader, "Info", 4)) + if (!memcmp(vbrheader, "Xing", 4) || !memcmp(vbrheader, "Info", 4)) { - int i = 8; /* Where to start parsing info */ - - /* DEBUGF("Xing/Info header\n"); */ + VDEBUGF("-- XING header --\n"); - /* Remember where in the file the Xing header is */ -/* Rockbox: not used - info->vbr_header_pos = lseek(fd, 0, SEEK_CUR) - info->frame_size; -*/ /* We want to skip the Xing frame when playing the stream */ bytecount += info->frame_size; - /* Now get the next frame to find out the real info about - the mp3 stream */ - header = find_next_frame(fd, &tmp, 0x20000, 0); - if(header == 0) - return -4; - - if(!mp3headerinfo(info, header)) - return -5; - - /* Is it a VBR file? */ - info->is_vbr = !memcmp(vbrheader, "Xing", 4); -/* Rockbox: not used - info->is_xing_vbr = info->is_vbr; -*/ - - if (vbrheader[7] & VBR_FRAMES_FLAG) /* Is the frame count there? */ - { - info->frame_count = bytes2int(vbrheader[i], vbrheader[i+1], - vbrheader[i+2], vbrheader[i+3]); - if (info->frame_count <= ULONG_MAX / info->ft_num) - info->file_time = info->frame_count * info->ft_num / info->ft_den; - else - info->file_time = info->frame_count / info->ft_den * info->ft_num; - i += 4; - } - - if (vbrheader[7] & VBR_BYTES_FLAG) /* Is byte count there? */ - { - info->byte_count = bytes2int(vbrheader[i], vbrheader[i+1], - vbrheader[i+2], vbrheader[i+3]); - i += 4; - } - - if (info->file_time && info->byte_count) - { - if (info->byte_count <= (ULONG_MAX/8)) - info->bitrate = info->byte_count * 8 / info->file_time; - else - info->bitrate = info->byte_count / (info->file_time >> 3); - } - - if (vbrheader[7] & VBR_TOC_FLAG) /* Is table-of-contents there? */ - { - info->has_toc = true; - memcpy( info->toc, vbrheader+i, 100 ); - i += 100; - } - if (vbrheader[7] & VBR_QUALITY_FLAG) - { - /* We don't care about this, but need to skip it */ - i += 4; - } -#if CONFIG_CODEC==SWCODEC - i += 21; - info->enc_delay = ((int)vbrheader[i ] << 4) | (vbrheader[i+1] >> 4); - info->enc_padding = ((int)vbrheader[i+1] << 8) | vbrheader[i+2]; - /* TODO: This sanity checking is rather silly, seeing as how the LAME - header contains a CRC field that can be used to verify integrity. */ - if (!(info->enc_delay >= 0 && info->enc_delay <= 2880 && - info->enc_padding >= 0 && info->enc_padding <= 2*1152)) - { - /* Invalid data */ - info->enc_delay = -1; - info->enc_padding = -1; - } -#endif + /* Now get the next frame to read the real info about the mp3 stream */ + result = get_next_header_info(fd, &bytecount, info); + if(result) + return result; + + get_xing_info(info, vbrheader); } - - if (!memcmp(vbrheader, "VBRI", 4)) + else if (!memcmp(vbrheader, "VBRI", 4)) { - VDEBUGF("VBRI header\n"); + VDEBUGF("-- VBRI header --\n"); /* We want to skip the VBRI frame when playing the stream */ bytecount += info->frame_size; - /* Now get the next frame to find out the real info about - the mp3 stream */ - header = find_next_frame(fd, &tmp, 0x20000, 0); - if(header == 0) - return -6; - - bytecount += tmp; - - if(!mp3headerinfo(info, header)) - return -7; - - VDEBUGF("%04x: %04x %04x ", 0, (short)(header >> 16), - (short)(header & 0xffff)); - for(i = 4;i < (int)sizeof(frame)-4;i+=2) { - if(i % 16 == 0) { - VDEBUGF("\n%04x: ", i-4); - } - VDEBUGF("%04x ", (frame[i-4] << 8) | frame[i-4+1]); - } - - VDEBUGF("\n"); - - /* Yes, it is a FhG VBR file */ - info->is_vbr = true; -/* Rockbox: not used - info->is_vbri_vbr = true; -*/ - info->has_toc = false; /* We don't parse the TOC (yet) */ - - info->byte_count = bytes2int(vbrheader[10], vbrheader[11], - vbrheader[12], vbrheader[13]); - info->frame_count = bytes2int(vbrheader[14], vbrheader[15], - vbrheader[16], vbrheader[17]); - if (info->frame_count <= ULONG_MAX / info->ft_num) - info->file_time = info->frame_count * info->ft_num / info->ft_den; - else - info->file_time = info->frame_count / info->ft_den * info->ft_num; - - if (info->byte_count <= (ULONG_MAX/8)) - info->bitrate = info->byte_count * 8 / info->file_time; - else - info->bitrate = info->byte_count / (info->file_time >> 3); - - /* We don't parse the TOC, since we don't yet know how to (FIXME) */ - num_offsets = bytes2int(0, 0, vbrheader[18], vbrheader[19]); - VDEBUGF("Frame size (%dkpbs): %d bytes (0x%x)\n", - info->bitrate, info->frame_size, info->frame_size); - VDEBUGF("Frame count: %lx\n", info->frame_count); - VDEBUGF("Byte count: %lx\n", info->byte_count); - VDEBUGF("Offsets: %d\n", num_offsets); - VDEBUGF("Frames/entry: %ld\n", - bytes2int(0, 0, vbrheader[24], vbrheader[25])); - - offset = 0; - - for(i = 0;i < num_offsets;i++) - { - j = bytes2int(0, 0, vbrheader[26+i*2], vbrheader[27+i*2]); - offset += j; - VDEBUGF("%03d: %lx (%x)\n", i, offset - bytecount, j); - } + /* Now get the next frame to read the real info about the mp3 stream */ + result = get_next_header_info(fd, &bytecount, info); + if(result) + return result; + + get_vbri_info(info, vbrheader); + } + else + { + VDEBUGF("-- No VBR header --\n"); } return bytecount; |