[FFmpeg-cvslog] escape124: Convert to the new bitstream reader
Alexandra Hájková
git at videolan.org
Mon Apr 3 21:38:38 EEST 2017
ffmpeg | branch: master | Alexandra Hájková <alexandra at khirnov.net> | Sat Apr 9 20:36:57 2016 +0200| [c43eb731721ac1009c2b4ca13f90ef00280119c9] | committer: Anton Khirnov
escape124: Convert to the new bitstream reader
Signed-off-by: Anton Khirnov <anton at khirnov.net>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c43eb731721ac1009c2b4ca13f90ef00280119c9
---
libavcodec/escape124.c | 85 ++++++++++++++++++++++++--------------------------
1 file changed, 41 insertions(+), 44 deletions(-)
diff --git a/libavcodec/escape124.c b/libavcodec/escape124.c
index 6d1b487..879f00a 100644
--- a/libavcodec/escape124.c
+++ b/libavcodec/escape124.c
@@ -21,7 +21,7 @@
#define BITSTREAM_READER_LE
#include "avcodec.h"
-#include "get_bits.h"
+#include "bitstream.h"
#include "internal.h"
typedef union MacroBlock {
@@ -48,8 +48,9 @@ typedef struct Escape124Context {
CodeBook codebooks[3];
} Escape124Context;
-static int can_safely_read(GetBitContext* gb, int bits) {
- return get_bits_left(gb) >= bits;
+static int can_safely_read(BitstreamContext *bc, int bits)
+{
+ return bitstream_bits_left(bc) >= bits;
}
/**
@@ -86,13 +87,13 @@ static av_cold int escape124_decode_close(AVCodecContext *avctx)
return 0;
}
-static CodeBook unpack_codebook(GetBitContext* gb, unsigned depth,
+static CodeBook unpack_codebook(BitstreamContext *bc, unsigned depth,
unsigned size)
{
unsigned i, j;
CodeBook cb = { 0 };
- if (!can_safely_read(gb, size * 34))
+ if (!can_safely_read(bc, size * 34))
return cb;
if (size >= INT_MAX / sizeof(MacroBlock))
@@ -104,9 +105,9 @@ static CodeBook unpack_codebook(GetBitContext* gb, unsigned depth,
cb.depth = depth;
cb.size = size;
for (i = 0; i < size; i++) {
- unsigned mask_bits = get_bits(gb, 4);
- unsigned color0 = get_bits(gb, 15);
- unsigned color1 = get_bits(gb, 15);
+ unsigned mask_bits = bitstream_read(bc, 4);
+ unsigned color0 = bitstream_read(bc, 15);
+ unsigned color1 = bitstream_read(bc, 15);
for (j = 0; j < 4; j++) {
if (mask_bits & (1 << j))
@@ -118,47 +119,43 @@ static CodeBook unpack_codebook(GetBitContext* gb, unsigned depth,
return cb;
}
-static unsigned decode_skip_count(GetBitContext* gb)
+static unsigned decode_skip_count(BitstreamContext *bc)
{
unsigned value;
// This function reads a maximum of 23 bits,
// which is within the padding space
- if (!can_safely_read(gb, 1))
+ if (!can_safely_read(bc, 1))
return -1;
- value = get_bits1(gb);
+ value = bitstream_read_bit(bc);
if (!value)
return value;
- value += get_bits(gb, 3);
+ value += bitstream_read(bc, 3);
if (value != (1 + ((1 << 3) - 1)))
return value;
- value += get_bits(gb, 7);
+ value += bitstream_read(bc, 7);
if (value != (1 + ((1 << 3) - 1)) + ((1 << 7) - 1))
return value;
- return value + get_bits(gb, 12);
+ return value + bitstream_read(bc, 12);
}
-static MacroBlock decode_macroblock(Escape124Context* s, GetBitContext* gb,
- int* codebook_index, int superblock_index)
+static MacroBlock decode_macroblock(Escape124Context *s, BitstreamContext *bc,
+ int *codebook_index, int superblock_index)
{
// This function reads a maximum of 22 bits; the callers
// guard this function appropriately
unsigned block_index, depth;
- int value = get_bits1(gb);
+ int value = bitstream_read_bit(bc);
if (value) {
static const char transitions[3][2] = { {2, 1}, {0, 2}, {1, 0} };
- value = get_bits1(gb);
+ value = bitstream_read_bit(bc);
*codebook_index = transitions[*codebook_index][value];
}
depth = s->codebooks[*codebook_index].depth;
-
- // depth = 0 means that this shouldn't read any bits;
- // in theory, this is the same as get_bits(gb, 0), but
- // that doesn't actually work.
- block_index = get_bitsz(gb, depth);
+ block_index = bitstream_read(bc, depth);
if (*codebook_index == 1) {
block_index += superblock_index << s->codebooks[1].depth;
@@ -208,7 +205,7 @@ static int escape124_decode_frame(AVCodecContext *avctx,
Escape124Context *s = avctx->priv_data;
AVFrame *frame = data;
- GetBitContext gb;
+ BitstreamContext bc;
unsigned frame_flags, frame_size;
unsigned i;
@@ -220,15 +217,15 @@ static int escape124_decode_frame(AVCodecContext *avctx,
unsigned old_stride, new_stride;
int ret;
- init_get_bits(&gb, buf, buf_size * 8);
+ bitstream_init(&bc, buf, buf_size * 8);
// This call also guards the potential depth reads for the
// codebook unpacking.
- if (!can_safely_read(&gb, 64))
+ if (!can_safely_read(&bc, 64))
return -1;
- frame_flags = get_bits_long(&gb, 32);
- frame_size = get_bits_long(&gb, 32);
+ frame_flags = bitstream_read(&bc, 32);
+ frame_size = bitstream_read(&bc, 32);
// Leave last frame unchanged
// FIXME: Is this necessary? I haven't seen it in any real samples
@@ -251,10 +248,10 @@ static int escape124_decode_frame(AVCodecContext *avctx,
if (i == 2) {
// This codebook can be cut off at places other than
// powers of 2, leaving some of the entries undefined.
- cb_size = get_bits_long(&gb, 20);
+ cb_size = bitstream_read(&bc, 20);
cb_depth = av_log2(cb_size - 1) + 1;
} else {
- cb_depth = get_bits(&gb, 4);
+ cb_depth = bitstream_read(&bc, 4);
if (i == 0) {
// This is the most basic codebook: pow(2,depth) entries
// for a depth-length key
@@ -267,7 +264,7 @@ static int escape124_decode_frame(AVCodecContext *avctx,
}
}
av_free(s->codebooks[i].blocks);
- s->codebooks[i] = unpack_codebook(&gb, cb_depth, cb_size);
+ s->codebooks[i] = unpack_codebook(&bc, cb_depth, cb_size);
if (!s->codebooks[i].blocks)
return -1;
}
@@ -292,7 +289,7 @@ static int escape124_decode_frame(AVCodecContext *avctx,
if (skip == -1) {
// Note that this call will make us skip the rest of the blocks
// if the frame prematurely ends
- skip = decode_skip_count(&gb);
+ skip = decode_skip_count(&bc);
}
if (skip) {
@@ -302,10 +299,10 @@ static int escape124_decode_frame(AVCodecContext *avctx,
copy_superblock(sb.pixels, 8,
old_frame_data, old_stride);
- while (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
+ while (can_safely_read(&bc, 1) && !bitstream_read_bit(&bc)) {
unsigned mask;
- mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
- mask = get_bits(&gb, 16);
+ mb = decode_macroblock(s, &bc, &cb_index, superblock_index);
+ mask = bitstream_read(&bc, 16);
multi_mask |= mask;
for (i = 0; i < 16; i++) {
if (mask & mask_matrix[i]) {
@@ -314,29 +311,29 @@ static int escape124_decode_frame(AVCodecContext *avctx,
}
}
- if (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
- unsigned inv_mask = get_bits(&gb, 4);
+ if (can_safely_read(&bc, 1) && !bitstream_read_bit(&bc)) {
+ unsigned inv_mask = bitstream_read(&bc, 4);
for (i = 0; i < 4; i++) {
if (inv_mask & (1 << i)) {
multi_mask ^= 0xF << i*4;
} else {
- multi_mask ^= get_bits(&gb, 4) << i*4;
+ multi_mask ^= bitstream_read(&bc, 4) << i * 4;
}
}
for (i = 0; i < 16; i++) {
if (multi_mask & mask_matrix[i]) {
- if (!can_safely_read(&gb, 1))
+ if (!can_safely_read(&bc, 1))
break;
- mb = decode_macroblock(s, &gb, &cb_index,
+ mb = decode_macroblock(s, &bc, &cb_index,
superblock_index);
insert_mb_into_sb(&sb, mb, i);
}
}
} else if (frame_flags & (1 << 16)) {
- while (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
- mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
- insert_mb_into_sb(&sb, mb, get_bits(&gb, 4));
+ while (can_safely_read(&bc, 1) && !bitstream_read_bit(&bc)) {
+ mb = decode_macroblock(s, &bc, &cb_index, superblock_index);
+ insert_mb_into_sb(&sb, mb, bitstream_read(&bc, 4));
}
}
@@ -358,7 +355,7 @@ static int escape124_decode_frame(AVCodecContext *avctx,
av_log(NULL, AV_LOG_DEBUG,
"Escape sizes: %i, %i, %i\n",
- frame_size, buf_size, get_bits_count(&gb) / 8);
+ frame_size, buf_size, bitstream_tell(&bc) / 8);
av_frame_unref(s->frame);
if ((ret = av_frame_ref(s->frame, frame)) < 0)
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