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Diffstat (limited to 'libavcodec/cbs_mpeg2.c')
-rw-r--r--libavcodec/cbs_mpeg2.c120
1 files changed, 63 insertions, 57 deletions
diff --git a/libavcodec/cbs_mpeg2.c b/libavcodec/cbs_mpeg2.c
index 3db10c5152..8b8b266563 100644
--- a/libavcodec/cbs_mpeg2.c
+++ b/libavcodec/cbs_mpeg2.c
@@ -1,18 +1,18 @@
/*
- * This file is part of Libav.
+ * This file is part of FFmpeg.
*
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
@@ -38,29 +38,34 @@
#define FUNC_MPEG2(rw, name) FUNC_NAME(rw, mpeg2, name)
#define FUNC(name) FUNC_MPEG2(READWRITE, name)
+#define SUBSCRIPTS(subs, ...) (subs > 0 ? ((int[subs + 1]){ subs, __VA_ARGS__ }) : NULL)
+
+#define ui(width, name) \
+ xui(width, name, current->name, 0)
+#define uis(width, name, subs, ...) \
+ xui(width, name, current->name, subs, __VA_ARGS__)
+
#define READ
#define READWRITE read
-#define RWContext BitstreamContext
+#define RWContext GetBitContext
-#define xui(width, name, var) do { \
+#define xui(width, name, var, subs, ...) do { \
uint32_t value = 0; \
CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \
+ SUBSCRIPTS(subs, __VA_ARGS__), \
&value, 0, (1 << width) - 1)); \
var = value; \
} while (0)
-#define ui(width, name) \
- xui(width, name, current->name)
-
#define marker_bit() do { \
av_unused uint32_t one; \
- CHECK(ff_cbs_read_unsigned(ctx, rw, 1, "marker_bit", &one, 1, 1)); \
+ CHECK(ff_cbs_read_unsigned(ctx, rw, 1, "marker_bit", NULL, &one, 1, 1)); \
} while (0)
#define nextbits(width, compare, var) \
- (bitstream_bits_left(rw) >= width && \
- (var = bitstream_peek(rw, width)) == (compare))
+ (get_bits_left(rw) >= width && \
+ (var = show_bits(rw, width)) == (compare))
#include "cbs_mpeg2_syntax_template.c"
@@ -68,7 +73,6 @@
#undef READWRITE
#undef RWContext
#undef xui
-#undef ui
#undef marker_bit
#undef nextbits
@@ -77,16 +81,14 @@
#define READWRITE write
#define RWContext PutBitContext
-#define xui(width, name, var) do { \
+#define xui(width, name, var, subs, ...) do { \
CHECK(ff_cbs_write_unsigned(ctx, rw, width, #name, \
+ SUBSCRIPTS(subs, __VA_ARGS__), \
var, 0, (1 << width) - 1)); \
} while (0)
-#define ui(width, name) \
- xui(width, name, current->name)
-
#define marker_bit() do { \
- CHECK(ff_cbs_write_unsigned(ctx, rw, 1, "marker_bit", 1, 1, 1)); \
+ CHECK(ff_cbs_write_unsigned(ctx, rw, 1, "marker_bit", NULL, 1, 1, 1)); \
} while (0)
#define nextbits(width, compare, var) (var)
@@ -97,7 +99,6 @@
#undef READWRITE
#undef RWContext
#undef xui
-#undef ui
#undef marker_bit
#undef nextbits
@@ -146,18 +147,12 @@ static int cbs_mpeg2_split_fragment(CodedBitstreamContext *ctx,
unit_size = (end - 4) - (start - 1);
}
- unit_data = av_malloc(unit_size + AV_INPUT_BUFFER_PADDING_SIZE);
- if (!unit_data)
- return AVERROR(ENOMEM);
- memcpy(unit_data, start - 1, unit_size);
- memset(unit_data + unit_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
+ unit_data = (uint8_t *)start - 1;
err = ff_cbs_insert_unit_data(ctx, frag, i, unit_type,
- unit_data, unit_size, NULL);
- if (err < 0) {
- av_freep(&unit_data);
+ unit_data, unit_size, frag->data_ref);
+ if (err < 0)
return err;
- }
if (end == frag->data + frag->data_size)
break;
@@ -172,10 +167,10 @@ static int cbs_mpeg2_split_fragment(CodedBitstreamContext *ctx,
static int cbs_mpeg2_read_unit(CodedBitstreamContext *ctx,
CodedBitstreamUnit *unit)
{
- BitstreamContext bc;
+ GetBitContext gbc;
int err;
- err = bitstream_init(&bc, unit->data, 8 * unit->data_size);
+ err = init_get_bits(&gbc, unit->data, 8 * unit->data_size);
if (err < 0)
return err;
@@ -189,24 +184,19 @@ static int cbs_mpeg2_read_unit(CodedBitstreamContext *ctx,
return err;
slice = unit->content;
- err = cbs_mpeg2_read_slice_header(ctx, &bc, &slice->header);
+ err = cbs_mpeg2_read_slice_header(ctx, &gbc, &slice->header);
if (err < 0)
return err;
- pos = bitstream_tell(&bc);
+ pos = get_bits_count(&gbc);
len = unit->data_size;
slice->data_size = len - pos / 8;
- slice->data_ref = av_buffer_alloc(slice->data_size +
- AV_INPUT_BUFFER_PADDING_SIZE);
+ slice->data_ref = av_buffer_ref(unit->data_ref);
if (!slice->data_ref)
return AVERROR(ENOMEM);
- slice->data = slice->data_ref->data;
+ slice->data = unit->data + pos / 8;
- memcpy(slice->data,
- unit->data + pos / 8, slice->data_size);
- memset(slice->data + slice->data_size, 0,
- AV_INPUT_BUFFER_PADDING_SIZE);
slice->data_bit_start = pos % 8;
} else {
@@ -220,7 +210,7 @@ static int cbs_mpeg2_read_unit(CodedBitstreamContext *ctx,
if (err < 0) \
return err; \
header = unit->content; \
- err = cbs_mpeg2_read_ ## read_func(ctx, &bc, header); \
+ err = cbs_mpeg2_read_ ## read_func(ctx, &gbc, header); \
if (err < 0) \
return err; \
} \
@@ -274,8 +264,6 @@ static int cbs_mpeg2_write_slice(CodedBitstreamContext *ctx,
PutBitContext *pbc)
{
MPEG2RawSlice *slice = unit->content;
- BitstreamContext bc;
- size_t bits_left;
int err;
err = cbs_mpeg2_write_slice_header(ctx, pbc, &slice->header);
@@ -283,21 +271,38 @@ static int cbs_mpeg2_write_slice(CodedBitstreamContext *ctx,
return err;
if (slice->data) {
+ size_t rest = slice->data_size - (slice->data_bit_start + 7) / 8;
+ uint8_t *pos = slice->data + slice->data_bit_start / 8;
+
+ av_assert0(slice->data_bit_start >= 0 &&
+ 8 * slice->data_size > slice->data_bit_start);
+
if (slice->data_size * 8 + 8 > put_bits_left(pbc))
return AVERROR(ENOSPC);
- bitstream_init(&bc, slice->data, slice->data_size * 8);
- bitstream_skip(&bc, slice->data_bit_start);
-
- while (bitstream_bits_left(&bc) > 15)
- put_bits(pbc, 16, bitstream_read(&bc, 16));
+ // First copy the remaining bits of the first byte
+ if (slice->data_bit_start % 8)
+ put_bits(pbc, 8 - slice->data_bit_start % 8,
+ *pos++ & MAX_UINT_BITS(8 - slice->data_bit_start % 8));
+
+ if (put_bits_count(pbc) % 8 == 0) {
+ // If the writer is aligned at this point,
+ // memcpy can be used to improve performance.
+ // This is the normal case.
+ flush_put_bits(pbc);
+ memcpy(put_bits_ptr(pbc), pos, rest);
+ skip_put_bytes(pbc, rest);
+ } else {
+ // If not, we have to copy manually:
+ for (; rest > 3; rest -= 4, pos += 4)
+ put_bits32(pbc, AV_RB32(pos));
- bits_left = bitstream_bits_left(&bc);
- put_bits(pbc, bits_left, bitstream_read(&bc, bits_left));
+ for (; rest; rest--, pos++)
+ put_bits(pbc, 8, *pos);
- // Align with zeroes.
- while (put_bits_count(pbc) % 8 != 0)
- put_bits(pbc, 1, 0);
+ // Align with zeros
+ put_bits(pbc, 8 - put_bits_count(pbc) % 8, 0);
+ }
}
return 0;
@@ -319,7 +324,7 @@ static int cbs_mpeg2_write_unit(CodedBitstreamContext *ctx,
if (err < 0) {
av_log(ctx->log_ctx, AV_LOG_ERROR, "Unable to allocate a "
"sufficiently large write buffer (last attempt "
- "%zu bytes).\n", priv->write_buffer_size);
+ "%"SIZE_SPECIFIER" bytes).\n", priv->write_buffer_size);
return err;
}
}
@@ -362,14 +367,14 @@ static int cbs_mpeg2_assemble_fragment(CodedBitstreamContext *ctx,
CodedBitstreamFragment *frag)
{
uint8_t *data;
- size_t size, dp, sp;
+ size_t size, dp;
int i;
size = 0;
for (i = 0; i < frag->nb_units; i++)
size += 3 + frag->units[i].data_size;
- frag->data_ref = av_buffer_alloc(size);
+ frag->data_ref = av_buffer_alloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!frag->data_ref)
return AVERROR(ENOMEM);
data = frag->data_ref->data;
@@ -382,12 +387,13 @@ static int cbs_mpeg2_assemble_fragment(CodedBitstreamContext *ctx,
data[dp++] = 0;
data[dp++] = 1;
- for (sp = 0; sp < unit->data_size; sp++)
- data[dp++] = unit->data[sp];
+ memcpy(data + dp, unit->data, unit->data_size);
+ dp += unit->data_size;
}
av_assert0(dp == size);
+ memset(data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
frag->data = data;
frag->data_size = size;
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-14 19:13:57 +0000