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dvb-sub: Use unchecked byte reader functions

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This commit is contained in:
Sebastian Dröge 2012-04-24 15:20:16 +02:00
parent 635a7f1c5d
commit 5d2b52697c
1 changed files with 28 additions and 26 deletions
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54
gst/dvbsuboverlay/dvb-sub.c
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@ -655,23 +655,24 @@ _dvb_sub_read_2bit_string (guint8 * destbuf, gint dbuf_len,
while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 0)) {
guint run_length = 0, clut_index = 0;
gst_bit_reader_get_bits_uint32 (&gb, &bits, 2);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
if (bits) { /* 2-bit_pixel-code */
run_length = 1;
clut_index = bits;
} else { /* 2-bit_zero */
gst_bit_reader_get_bits_uint32 (&gb, &bits, 1);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 1) { /* switch_1 == '1' */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 3);
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 3);
run_length += 3;
gst_bit_reader_get_bits_uint32 (&gb, &clut_index, 2);
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
} else { /* switch_1 == '0' */
gst_bit_reader_get_bits_uint32 (&gb, &bits, 1);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 1) { /* switch_2 == '1' */
run_length = 1; /* 1x pseudo-colour '00' */
} else { /* switch_2 == '0' */
gst_bit_reader_get_bits_uint32 (&gb, &bits, 2);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
switch (bits) { /* switch_3 */
case 0x0: /* end of 2-bit/pixel_code_string */
stop_parsing = TRUE;
@ -680,14 +681,14 @@ _dvb_sub_read_2bit_string (guint8 * destbuf, gint dbuf_len,
run_length = 2;
break;
case 0x2: /* the following 6 bits contain run length coded pixel data */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 4);
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
run_length += 12;
gst_bit_reader_get_bits_uint32 (&gb, &clut_index, 2);
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
break;
case 0x3: /* the following 10 bits contain run length coded pixel data */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 8);
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 8);
run_length += 29;
gst_bit_reader_get_bits_uint32 (&gb, &clut_index, 2);
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
break;
}
}
@ -747,28 +748,29 @@ _dvb_sub_read_4bit_string (guint8 * destbuf, gint dbuf_len,
while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 0)) {
guint run_length = 0, clut_index = 0;
gst_bit_reader_get_bits_uint32 (&gb, &bits, 4);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
if (bits) {
run_length = 1;
clut_index = bits;
} else {
gst_bit_reader_get_bits_uint32 (&gb, &bits, 1);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 0) { /* switch_1 == '0' */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 3);
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 3);
if (!run_length) {
stop_parsing = TRUE;
} else {
run_length += 2;
}
} else { /* switch_1 == '1' */
gst_bit_reader_get_bits_uint32 (&gb, &bits, 1);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 0) { /* switch_2 == '0' */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 2);
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
run_length += 4;
gst_bit_reader_get_bits_uint32 (&gb, &clut_index, 4);
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
} else { /* switch_2 == '1' */
gst_bit_reader_get_bits_uint32 (&gb, &bits, 2);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
switch (bits) {
case 0x0: /* switch_3 == '00' */
run_length = 1; /* 1 pixel of pseudo-color 0 */
@ -777,14 +779,14 @@ _dvb_sub_read_4bit_string (guint8 * destbuf, gint dbuf_len,
run_length = 2; /* 2 pixels of pseudo-color 0 */
break;
case 0x2: /* switch_3 == '10' */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 4);
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
run_length += 9;
gst_bit_reader_get_bits_uint32 (&gb, &clut_index, 4);
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
break;
case 0x3: /* switch_3 == '11' */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 8);
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 8);
run_length += 25;
gst_bit_reader_get_bits_uint32 (&gb, &clut_index, 4);
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
break;
}
}
@ -858,23 +860,23 @@ _dvb_sub_read_8bit_string (guint8 * destbuf, gint dbuf_len,
/* Rephrased - it's better to work with bytes with default value '0' instead of reading from memory we don't own. */
while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 0)) {
guint run_length = 0, clut_index = 0;
gst_bit_reader_get_bits_uint32 (&gb, &bits, 8);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 8);
if (bits) { /* 8-bit_pixel-code */
run_length = 1;
clut_index = bits;
} else { /* 8-bit_zero */
gst_bit_reader_get_bits_uint32 (&gb, &bits, 1);
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 0) { /* switch_1 == '0' */
/* run_length_1-127 for pseudo-colour _entry) '0x00' */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 7);
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 7);
if (run_length == 0) { /* end_of_string_signal */
stop_parsing = TRUE;
}
} else { /* switch_1 == '1' */
/* run_length_3-127 */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 7);
gst_bit_reader_get_bits_uint32 (&gb, &clut_index, 8);
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 7);
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 8);
if (run_length < 3) {
GST_WARNING ("runlength value was %u, but the spec requires it "