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-rw-r--r--libavcodec/bitstream.h28
-rw-r--r--libavcodec/dvdec.c94
2 files changed, 69 insertions, 53 deletions
diff --git a/libavcodec/bitstream.h b/libavcodec/bitstream.h
index 996e32e..894a13e 100644
--- a/libavcodec/bitstream.h
+++ b/libavcodec/bitstream.h
@@ -384,4 +384,32 @@ static inline int bitstream_apply_sign(BitstreamContext *bc, int val)
return (val ^ sign) - sign;
}
+/* Unwind the cache so a refill_32 can fill it again. */
+static inline void bitstream_unwind(BitstreamContext *bc)
+{
+ int unwind = 4;
+ int unwind_bits = unwind * 8;
+
+ if (bc->bits_left < unwind_bits)
+ return;
+
+ bc->bits >>= unwind_bits;
+ bc->bits <<= unwind_bits;
+ bc->bits_left -= unwind_bits;
+ bc->ptr -= unwind;
+}
+
+/* Unget up to 32 bits. */
+static inline void bitstream_unget(BitstreamContext *bc, uint64_t value,
+ size_t amount)
+{
+ size_t cache_size = sizeof(bc->bits) * 8;
+
+ if (bc->bits_left + amount > cache_size)
+ bitstream_unwind(bc);
+
+ bc->bits = (bc->bits >> amount) | (value << (cache_size - amount));
+ bc->bits_left += amount;
+}
+
#endif /* AVCODEC_BITSTREAM_H */
diff --git a/libavcodec/dvdec.c b/libavcodec/dvdec.c
index dc37a5e..a2f0171 100644
--- a/libavcodec/dvdec.c
+++ b/libavcodec/dvdec.c
@@ -40,9 +40,9 @@
#include "libavutil/pixdesc.h"
#include "avcodec.h"
+#include "bitstream.h"
#include "dv.h"
#include "dvdata.h"
-#include "get_bits.h"
#include "idctdsp.h"
#include "internal.h"
#include "put_bits.h"
@@ -80,51 +80,34 @@ static av_cold int dvvideo_decode_init(AVCodecContext *avctx)
}
/* decode AC coefficients */
-static void dv_decode_ac(GetBitContext *gb, BlockInfo *mb, int16_t *block)
+static void dv_decode_ac(BitstreamContext *bc, BlockInfo *mb, int16_t *block)
{
- int last_index = gb->size_in_bits;
const uint8_t *scan_table = mb->scan_table;
const uint32_t *factor_table = mb->factor_table;
int pos = mb->pos;
int partial_bit_count = mb->partial_bit_count;
- int level, run, vlc_len, index;
-
- OPEN_READER_NOSIZE(re, gb);
- UPDATE_CACHE(re, gb);
+ int level, run;
/* if we must parse a partial VLC, we do it here */
if (partial_bit_count > 0) {
- re_cache = re_cache >> partial_bit_count |
- mb->partial_bit_buffer;
- re_index -= partial_bit_count;
+ bitstream_unget(bc, mb->partial_bit_buffer, partial_bit_count);
mb->partial_bit_count = 0;
}
/* get the AC coefficients until last_index is reached */
for (;;) {
- ff_dlog(NULL, "%2d: bits=%04x index=%u\n", pos, SHOW_UBITS(re, gb, 16),
- re_index);
- /* our own optimized GET_RL_VLC */
- index = NEG_USR32(re_cache, TEX_VLC_BITS);
- vlc_len = ff_dv_rl_vlc[index].len;
- if (vlc_len < 0) {
- index = NEG_USR32((unsigned) re_cache << TEX_VLC_BITS, -vlc_len) +
- ff_dv_rl_vlc[index].level;
- vlc_len = TEX_VLC_BITS - vlc_len;
- }
- level = ff_dv_rl_vlc[index].level;
- run = ff_dv_rl_vlc[index].run;
-
- /* gotta check if we're still within gb boundaries */
- if (re_index + vlc_len > last_index) {
- /* should be < 16 bits otherwise a codeword could have been parsed */
- mb->partial_bit_count = last_index - re_index;
- mb->partial_bit_buffer = re_cache & ~(-1u >> mb->partial_bit_count);
- re_index = last_index;
+ BitstreamContext tmp = *bc;
+
+ ff_dlog(NULL, "%2d: bits=%04x index=%d\n",
+ pos, bitstream_peek(bc, 16), bitstream_tell(bc));
+
+ BITSTREAM_RL_VLC(level, run, bc, ff_dv_rl_vlc, TEX_VLC_BITS, 2);
+
+ if (bitstream_bits_left(bc) < 0) {
+ mb->partial_bit_count = bitstream_bits_left(&tmp);
+ mb->partial_bit_buffer = bitstream_peek(&tmp, mb->partial_bit_count);
break;
}
- re_index += vlc_len;
-
ff_dlog(NULL, "run=%d level=%d\n", run, level);
pos += run;
if (pos >= 64)
@@ -133,22 +116,22 @@ static void dv_decode_ac(GetBitContext *gb, BlockInfo *mb, int16_t *block)
level = (level * factor_table[pos] + (1 << (dv_iweight_bits - 1))) >>
dv_iweight_bits;
block[scan_table[pos]] = level;
-
- UPDATE_CACHE(re, gb);
}
- CLOSE_READER(re, gb);
mb->pos = pos;
}
-static inline void bit_copy(PutBitContext *pb, GetBitContext *gb)
+static inline void bit_copy(PutBitContext *pb, BitstreamContext *bc)
{
- int bits_left = get_bits_left(gb);
- while (bits_left >= MIN_CACHE_BITS) {
- put_bits(pb, MIN_CACHE_BITS, get_bits(gb, MIN_CACHE_BITS));
- bits_left -= MIN_CACHE_BITS;
+ int bits_left = bitstream_bits_left(bc);
+
+ while (bits_left >= 32) {
+ int read = bitstream_read(bc, 32);
+ put_bits32(pb, read);
+ bits_left -= 32;
}
+
if (bits_left > 0)
- put_bits(pb, bits_left, get_bits(gb, bits_left));
+ put_bits(pb, bits_left, bitstream_read(bc, bits_left));
}
/* mb_x and mb_y are in units of 8 pixels */
@@ -164,13 +147,14 @@ static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
uint8_t *y_ptr;
const uint8_t *buf_ptr;
PutBitContext pb, vs_pb;
- GetBitContext gb;
+ BitstreamContext bc;
BlockInfo mb_data[5 * DV_MAX_BPM], *mb, *mb1;
LOCAL_ALIGNED_16(int16_t, sblock, [5 * DV_MAX_BPM], [64]);
LOCAL_ALIGNED_16(uint8_t, mb_bit_buffer, [80 + AV_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
LOCAL_ALIGNED_16(uint8_t, vs_bit_buffer, [80 * 5 + AV_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
const int log2_blocksize = 3;
int is_field_mode[5];
+ int mb_bits;
assert((((int) mb_bit_buffer) & 7) == 0);
assert((((int) vs_bit_buffer) & 7) == 0);
@@ -192,12 +176,12 @@ static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
is_field_mode[mb_index] = 0;
for (j = 0; j < s->sys->bpm; j++) {
last_index = s->sys->block_sizes[j];
- init_get_bits(&gb, buf_ptr, last_index);
+ bitstream_init(&bc, buf_ptr, last_index);
/* get the DC */
- dc = get_sbits(&gb, 9);
- dct_mode = get_bits1(&gb);
- class1 = get_bits(&gb, 2);
+ dc = bitstream_read_signed(&bc, 9);
+ dct_mode = bitstream_read_bit(&bc);
+ class1 = bitstream_read(&bc, 2);
if (DV_PROFILE_IS_HD(s->sys)) {
mb->idct_put = s->idct_put[0];
mb->scan_table = s->dv_zigzag[0];
@@ -223,12 +207,12 @@ static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
mb->partial_bit_count = 0;
ff_dlog(avctx, "MB block: %d, %d ", mb_index, j);
- dv_decode_ac(&gb, mb, block);
+ dv_decode_ac(&bc, mb, block);
/* write the remaining bits in a new buffer only if the
* block is finished */
if (mb->pos >= 64)
- bit_copy(&pb, &gb);
+ bit_copy(&pb, &bc);
block += 64;
mb++;
@@ -238,12 +222,15 @@ static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
ff_dlog(avctx, "***pass 2 size=%d MB#=%d\n", put_bits_count(&pb), mb_index);
block = block1;
mb = mb1;
- init_get_bits(&gb, mb_bit_buffer, put_bits_count(&pb));
+
+ mb_bits = put_bits_count(&pb);
put_bits32(&pb, 0); // padding must be zeroed
flush_put_bits(&pb);
+ bitstream_init(&bc, mb_bit_buffer, mb_bits);
+
for (j = 0; j < s->sys->bpm; j++, block += 64, mb++) {
- if (mb->pos < 64 && get_bits_left(&gb) > 0) {
- dv_decode_ac(&gb, mb, block);
+ if (mb->pos < 64 && bitstream_bits_left(&bc) > 0) {
+ dv_decode_ac(&bc, mb, block);
/* if still not finished, no need to parse other blocks */
if (mb->pos < 64)
break;
@@ -252,21 +239,22 @@ static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
/* all blocks are finished, so the extra bytes can be used at
* the video segment level */
if (j >= s->sys->bpm)
- bit_copy(&vs_pb, &gb);
+ bit_copy(&vs_pb, &bc);
}
/* we need a pass over the whole video segment */
ff_dlog(avctx, "***pass 3 size=%d\n", put_bits_count(&vs_pb));
block = &sblock[0][0];
mb = mb_data;
- init_get_bits(&gb, vs_bit_buffer, put_bits_count(&vs_pb));
+ mb_bits = put_bits_count(&vs_pb);
put_bits32(&vs_pb, 0); // padding must be zeroed
flush_put_bits(&vs_pb);
+ bitstream_init(&bc, vs_bit_buffer, mb_bits);
for (mb_index = 0; mb_index < 5; mb_index++) {
for (j = 0; j < s->sys->bpm; j++) {
if (mb->pos < 64) {
ff_dlog(avctx, "start %d:%d\n", mb_index, j);
- dv_decode_ac(&gb, mb, block);
+ dv_decode_ac(&bc, mb, block);
}
if (mb->pos >= 64 && mb->pos < 127)
av_log(avctx, AV_LOG_ERROR,
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