commit de035c3cfa75c7e12eb9ee4df5e604437bc02c6f
parent 753a864dd77c67ec29c9657855d6db1a351110a0
Author: Heikki Lindholm <holin@iki.fi>
Date: Sun, 13 Jul 2008 20:00:00 +0000
fix endian issues, nicer "format" line
Diffstat:
1 file changed, 86 insertions(+), 49 deletions(-)
diff --git a/src/plugins/mp3extractor.c b/src/plugins/mp3extractor.c
@@ -210,15 +210,22 @@ enum
enum
{ LAYER_ERR = 0, LAYER_1 = 1, LAYER_2 = 2, LAYER_3 = 3 };
-#define sync_mask ((unsigned int) 0xE0FF)
-#define mpeg_ver_mask ((unsigned int) 0x1800)
-#define mpeg_layer_mask ((unsigned int)0x600)
-#define bitrate_mask ((unsigned int)0xF00000)
-#define freq_mask ((unsigned int)0xC0000)
-#define ch_mask ((unsigned int)0xC0000000)
-#define pad_mask ((unsigned int)0x20000)
-
-unsigned int bitrate_table[16][6] = {
+#define MPA_SYNC_MASK ((unsigned int) 0xFFE00000)
+#define MPA_LAST_SYNC_BIT_MASK ((unsigned int) 0x00100000)
+#define MPA_VERSION_MASK ((unsigned int) 0x00080000)
+#define MPA_LAYER_MASK ((unsigned int) 0x3)
+#define MPA_LAYER_SHIFT 17
+#define MPA_BITRATE_MASK ((unsigned int) 0xF)
+#define MPA_BITRATE_SHIFT 12
+#define MPA_FREQ_MASK ((unsigned int) 0x3)
+#define MPA_FREQ_SHIFT 10
+#define MPA_CHMODE_MASK ((unsigned int) 0x3)
+#define MPA_CHMODE_SHIFT 6
+#define MPA_PADDING_SHIFT 9
+#define MPA_COPYRIGHT_SHIFT 3
+#define MPA_ORIGINAL_SHIFT 2
+
+static const unsigned int bitrate_table[16][6] = {
{0, 0, 0, 0, 0, 0},
{32, 32, 32, 32, 32, 8},
{64, 48, 40, 64, 48, 16},
@@ -236,11 +243,27 @@ unsigned int bitrate_table[16][6] = {
{448, 384, 320, 448, 384, 320},
{-1, -1, -1, -1, -1, -1}
};
-int freq_table[4][3] = {
+static const int freq_table[4][3] = {
{44100, 22050, 11025},
{48000, 24000, 12000},
{32000, 16000, 8000}
};
+static const char * const channel_modes[4] = {
+ gettext_noop("stereo"),
+ gettext_noop("joint stereo"),
+ gettext_noop("dual channel"),
+ gettext_noop("mono")
+};
+static const char * const mpeg_versions[3] = {
+ gettext_noop("MPEG-1"),
+ gettext_noop("MPEG-2"),
+ gettext_noop("MPEG-2.5")
+};
+static const char * const layer_names[3] = {
+ gettext_noop("Layer I"),
+ gettext_noop("Layer II"),
+ gettext_noop("Layer III")
+};
#define OK 0
@@ -314,16 +337,18 @@ addkword (EXTRACTOR_KeywordList * oldhead,
static struct EXTRACTOR_Keywords *
-mp3parse (const char *data, size_t size, struct EXTRACTOR_Keywords *prev)
+mp3parse (const unsigned char *data, size_t size, struct EXTRACTOR_Keywords *prev)
{
unsigned int header;
int counter = 0;
char mpeg_ver = 0;
- char layer_ver = 0;
+ char layer = 0;
int idx_num = 0;
int bitrate = 0; /*used for each frame */
int avg_bps = 0; /*average bitrate */
int vbr_flag = 0;
+ int copyright_flag = 0;
+ int original_flag = 0;
int length = 0;
int sample_rate = 0;
int ch = 0;
@@ -339,8 +364,9 @@ mp3parse (const char *data, size_t size, struct EXTRACTOR_Keywords *prev)
{
return prev;
} /*unable to find header */
- memcpy (&header, &data[pos], sizeof (header));
- if ((header & sync_mask) == sync_mask)
+ header = (data[pos] << 24) | (data[pos+1] << 16) |
+ (data[pos+2] << 8) | data[pos+3];
+ if ((header & MPA_SYNC_MASK) == MPA_SYNC_MASK)
break; /*found header sync */
pos++;
counter++; /*next try */
@@ -356,63 +382,63 @@ mp3parse (const char *data, size_t size, struct EXTRACTOR_Keywords *prev)
do
{ /*ok, now we found a mp3 frame header */
frames++;
- switch (header & mpeg_ver_mask)
+ switch (header & (MPA_LAST_SYNC_BIT_MASK | MPA_VERSION_MASK))
{
- case 0x1000:
- mpeg_ver = MPEG_ERR; /*error */
+ case (MPA_LAST_SYNC_BIT_MASK | MPA_VERSION_MASK):
+ mpeg_ver = MPEG_V1;
break;
- case 0x800:
- prev = addkword (prev, "MPEG V2", EXTRACTOR_RESOURCE_TYPE);
+ case (MPA_LAST_SYNC_BIT_MASK):
mpeg_ver = MPEG_V2;
break;
- case 0x1800:
- prev = addkword (prev, "MPEG V1", EXTRACTOR_RESOURCE_TYPE);
- mpeg_ver = MPEG_V1;
- break;
case 0:
- prev = addkword (prev, "MPEG V25", EXTRACTOR_RESOURCE_TYPE);
mpeg_ver = MPEG_V25;
break;
+ case (MPA_VERSION_MASK):
+ default:
+ mpeg_ver = MPEG_ERR; /*error */
+ break;
}
- switch (header & mpeg_layer_mask)
+ switch (header & (MPA_LAYER_MASK << MPA_LAYER_SHIFT))
{
- case 0x400:
- layer_ver = LAYER_2;
+ case (0x1 << MPA_LAYER_SHIFT):
+ layer = LAYER_3;
break;
- case 0x200:
- layer_ver = LAYER_3;
+ case (0x2 << MPA_LAYER_SHIFT):
+ layer = LAYER_2;
break;
- case 0x600:
- layer_ver = LAYER_1;
+ case (0x3 << MPA_LAYER_SHIFT):
+ layer = LAYER_1;
break;
- case 0:
- layer_ver = LAYER_ERR; /*error */
+ case 0x0:
+ default:
+ layer = LAYER_ERR; /*error */
}
- if (!layer_ver || !mpeg_ver)
+ if (!layer || !mpeg_ver)
return prev; /*unknown mpeg type */
if (mpeg_ver < 3)
- idx_num = (mpeg_ver - 1) * 3 + layer_ver - 1;
+ idx_num = (mpeg_ver - 1) * 3 + layer - 1;
else
- idx_num = 2 + layer_ver;
- bitrate = 1000 * bitrate_table[(header & bitrate_mask) >> 20][idx_num];
+ idx_num = 2 + layer;
+ bitrate = 1000 * bitrate_table[(header >> MPA_BITRATE_SHIFT) &
+ MPA_BITRATE_MASK][idx_num];
if (bitrate < 0)
{
frames--;
break;
} /*error in header */
- sample_rate = freq_table[(header & freq_mask) >> 18][mpeg_ver - 1];
+ sample_rate = freq_table[(header >> MPA_FREQ_SHIFT) &
+ MPA_FREQ_MASK][mpeg_ver - 1];
if (sample_rate < 0)
{
frames--;
break;
} /*error in header */
- if ((header & ch_mask) == ch_mask)
- ch = 1;
- else
- ch = 2; /*stereo non stereo select */
+ ch = ((header >> MPA_CHMODE_SHIFT) & MPA_CHMODE_MASK);
+ copyright_flag = (header >> MPA_COPYRIGHT_SHIFT) & 0x1;
+ original_flag = (header >> MPA_ORIGINAL_SHIFT) & 0x1;
frame_size =
144 * bitrate / (sample_rate ? sample_rate : 1) +
- ((header & pad_mask) >> 17);
+ ((header >> MPA_PADDING_SHIFT) & 0x1);
avg_bps += bitrate / 1000;
pos += frame_size - 4;
@@ -422,9 +448,10 @@ mp3parse (const char *data, size_t size, struct EXTRACTOR_Keywords *prev)
vbr_flag = 1;
if (pos + sizeof (header) > size)
break; /* EOF */
- memcpy (&header, &data[pos], sizeof (header));
+ header = (data[pos] << 24) | (data[pos+1] << 16) |
+ (data[pos+2] << 8) | data[pos+3];
}
- while ((header & sync_mask) == sync_mask);
+ while ((header & MPA_SYNC_MASK) == MPA_SYNC_MASK);
if (!frames)
return prev; /*no valid frames */
@@ -439,11 +466,21 @@ mp3parse (const char *data, size_t size, struct EXTRACTOR_Keywords *prev)
length = 1152 * frames / (sample_rate ? sample_rate : 0xFFFFFFFF);
}
+ prev = addkword (prev, mpeg_versions[mpeg_ver-1], EXTRACTOR_RESOURCE_TYPE);
format = malloc (512);
- snprintf (format, 512, "%d kbps, %d hz, %dm%02d %s %s", avg_bps, sample_rate, length / 60, length % 60, /* minutes / seconds */
- ch == 2 ? _("stereo") : _("mono"),
- vbr_flag ? _("(variable bps)") : "");
+ snprintf (format, 512, "%s %s audio, %d kbps (%s), %d Hz, %s, %s, %s",
+ mpeg_versions[mpeg_ver-1],
+ layer_names[layer-1],
+ avg_bps,
+ vbr_flag ? _("VBR") : _("CBR"),
+ sample_rate,
+ channel_modes[ch],
+ copyright_flag ? _("copyright") : _("no copyright"),
+ original_flag ? _("original") : _("copy") );
prev = addkword (prev, format, EXTRACTOR_FORMAT);
+ snprintf (format, 512, "%dm%02d",
+ length / 60, length % 60);
+ prev = addkword (prev, format, EXTRACTOR_DURATION);
free (format);
return prev;
}
@@ -493,7 +530,7 @@ libextractor_mp3_extract (const char *filename,
free (info.artist);
free (info.comment);
- return mp3parse (data, size, klist);
+ return mp3parse ((unsigned char *) data, size, klist);
}
/* end of mp3extractor.c */
