mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2025-02-21 13:36:39 +00:00
Code Issues 1 Projects Releases Wiki Activity

dvb-sub: Use unchecked byte reader functions

Browse source
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
Show stats Download patch file Download diff file Expand all files Collapse all files

54
gst/dvbsuboverlay/dvb-sub.c
View file

@ -655,23 +655,24 @@ _dvb_sub_read_2bit_string (guint8 * destbuf, gint dbuf_len,
while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 0)) { while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 0)) {
guint run_length = 0, clut_index = 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 */ if (bits) { /* 2-bit_pixel-code */
run_length = 1; run_length = 1;
clut_index = bits; clut_index = bits;
} else { /* 2-bit_zero */ } 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' */ 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; 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' */ } 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' */ if (bits == 1) { /* switch_2 == '1' */
run_length = 1; /* 1x pseudo-colour '00' */ run_length = 1; /* 1x pseudo-colour '00' */
} else { /* switch_2 == '0' */ } 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 */ switch (bits) { /* switch_3 */
case 0x0: /* end of 2-bit/pixel_code_string */ case 0x0: /* end of 2-bit/pixel_code_string */
stop_parsing = TRUE; stop_parsing = TRUE;
@ -680,14 +681,14 @@ _dvb_sub_read_2bit_string (guint8 * destbuf, gint dbuf_len,
run_length = 2; run_length = 2;
break; break;
case 0x2: /* the following 6 bits contain run length coded pixel data */ 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; 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; break;
case 0x3: /* the following 10 bits contain run length coded pixel data */ 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; 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; 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)) { while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 0)) {
guint run_length = 0, clut_index = 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) { if (bits) {
run_length = 1; run_length = 1;
clut_index = bits; clut_index = bits;
} else { } 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' */ 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) { if (!run_length) {
stop_parsing = TRUE; stop_parsing = TRUE;
} else { } else {
run_length += 2; run_length += 2;
} }
} else { /* switch_1 == '1' */ } 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' */ 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; 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' */ } 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) { switch (bits) {
case 0x0: /* switch_3 == '00' */ case 0x0: /* switch_3 == '00' */
run_length = 1; /* 1 pixel of pseudo-color 0 */ 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 */ run_length = 2; /* 2 pixels of pseudo-color 0 */
break; break;
case 0x2: /* switch_3 == '10' */ 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; 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; break;
case 0x3: /* switch_3 == '11' */ 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; 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; 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. */ /* 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)) { while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 0)) {
guint run_length = 0, clut_index = 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 */ if (bits) { /* 8-bit_pixel-code */
run_length = 1; run_length = 1;
clut_index = bits; clut_index = bits;
} else { /* 8-bit_zero */ } 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' */ if (bits == 0) { /* switch_1 == '0' */
/* run_length_1-127 for pseudo-colour _entry) '0x00' */ /* 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 */ if (run_length == 0) { /* end_of_string_signal */
stop_parsing = TRUE; stop_parsing = TRUE;
} }
} else { /* switch_1 == '1' */ } else { /* switch_1 == '1' */
/* run_length_3-127 */ /* run_length_3-127 */
gst_bit_reader_get_bits_uint32 (&gb, &run_length, 7); run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 7);
gst_bit_reader_get_bits_uint32 (&gb, &clut_index, 8); clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 8);
if (run_length < 3) { if (run_length < 3) {
GST_WARNING ("runlength value was %u, but the spec requires it " GST_WARNING ("runlength value was %u, but the spec requires it "