avcodec: move leb reading functions to its own header

Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/av1_parse.h

@@ -30,6 +30,7 @@
 
 #include "av1.h"
 #include "get_bits.h"
+#include "leb.h"
 
 // OBU header fields + max leb128 length
 #define MAX_OBU_HEADER_SIZE (2 + 8)
@@ -88,19 +89,6 @@ int ff_av1_packet_split(AV1Packet *pkt, const uint8_t *buf, int length,
  */
 void ff_av1_packet_uninit(AV1Packet *pkt);
 
-static inline int64_t leb128(GetBitContext *gb) {
-    int64_t ret = 0;
-    int i;
-
-    for (i = 0; i < 8; i++) {
-        int byte = get_bits(gb, 8);
-        ret |= (int64_t)(byte & 0x7f) << (i * 7);
-        if (!(byte & 0x80))
-            break;
-    }
-    return ret;
-}
-
 static inline int parse_obu_header(const uint8_t *buf, int buf_size,
                                    int64_t *obu_size, int *start_pos, int *type,
                                    int *temporal_id, int *spatial_id)
@@ -129,7 +117,7 @@ static inline int parse_obu_header(const uint8_t *buf, int buf_size,
         *temporal_id = *spatial_id = 0;
     }
 
-    *obu_size  = has_size_flag ? leb128(&gb)
+    *obu_size  = has_size_flag ? get_leb128(&gb)
                                : buf_size - 1 - extension_flag;
 
     if (get_bits_left(&gb) < 0)

libavcodec/bitstream.h

@@ -103,7 +103,6 @@
 # define bits_apply_sign    bits_apply_sign_le
 # define bits_read_vlc      bits_read_vlc_le
 # define bits_read_vlc_multi bits_read_vlc_multi_le
-# define bits_read_leb      bits_read_leb_le
 
 #elif defined(BITS_DEFAULT_BE)
 
@@ -133,7 +132,6 @@
 # define bits_apply_sign    bits_apply_sign_be
 # define bits_read_vlc      bits_read_vlc_be
 # define bits_read_vlc_multi bits_read_vlc_multi_be
-# define bits_read_leb      bits_read_leb_be
 
 #endif
 

libavcodec/bitstream_template.h

@@ -562,29 +562,6 @@ static inline int BS_FUNC(read_vlc_multi)(BSCTX *bc, uint8_t dst[8],
     return ret;
 }
 
-/**
- * Read a unsigned integer coded as a variable number of up to eight
- * little-endian bytes, where the MSB in a byte signals another byte
- * must be read.
- * Values > UINT_MAX are truncated, but all coded bits are read.
- */
-static inline unsigned BS_FUNC(read_leb)(BSCTX *bc) {
-    int more, i = 0;
-    unsigned leb = 0;
-
-    do {
-        int byte = BS_FUNC(read)(bc, 8);
-        unsigned bits = byte & 0x7f;
-        more = byte & 0x80;
-        if (i <= 4)
-            leb |= bits << (i * 7);
-        if (++i == 8)
-            break;
-    } while (more);
-
-    return leb;
-}
-
 #undef BSCTX
 #undef BS_FUNC
 #undef BS_JOIN3

libavcodec/bsf/extract_extradata.c

@@ -68,7 +68,7 @@ static int metadata_is_global(const AV1OBU *obu)
     if (init_get_bits(&gb, obu->data, obu->size_bits) < 0)
         return 0;
 
-    metadata_type = leb128(&gb);
+    metadata_type = get_leb(&gb);
 
     return val_in_array(metadata_obu_types, FF_ARRAY_ELEMS(metadata_obu_types),
                         metadata_type);

libavcodec/get_bits.h

@@ -94,7 +94,6 @@ typedef BitstreamContext GetBitContext;
 #define align_get_bits      bits_align
 #define get_vlc2            bits_read_vlc
 #define get_vlc_multi       bits_read_vlc_multi
-#define get_leb             bits_read_leb
 
 #define init_get_bits8_le(s, buffer, byte_size) bits_init8_le((BitstreamContextLE*)s, buffer, byte_size)
 #define get_bits_le(s, n)                       bits_read_le((BitstreamContextLE*)s, n)
@@ -711,29 +710,6 @@ static inline int skip_1stop_8data_bits(GetBitContext *gb)
     return 0;
 }
 
-/**
- * Read a unsigned integer coded as a variable number of up to eight
- * little-endian bytes, where the MSB in a byte signals another byte
- * must be read.
- * All coded bits are read, but values > UINT_MAX are truncated.
- */
-static inline unsigned get_leb(GetBitContext *s) {
-    int more, i = 0;
-    unsigned leb = 0;
-
-    do {
-        int byte = get_bits(s, 8);
-        unsigned bits = byte & 0x7f;
-        more = byte & 0x80;
-        if (i <= 4)
-            leb |= bits << (i * 7);
-        if (++i == 8)
-            break;
-    } while (more);
-
-    return leb;
-}
-
 #endif // CACHED_BITSTREAM_READER
 
 #endif /* AVCODEC_GET_BITS_H */

libavcodec/leb.h

@@ -0,0 +1,70 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * 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.
+ *
+ * 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * leb128 handling implementations
+ */
+
+#ifndef AVCODEC_LEB_H
+#define AVCODEC_LEB_H
+
+#include "get_bits.h"
+
+/**
+ * Read a unsigned integer coded as a variable number of up to eight
+ * little-endian bytes, where the MSB in a byte signals another byte
+ * must be read.
+ * All coded bits are read, but values > UINT_MAX are truncated.
+ */
+static inline unsigned get_leb(GetBitContext *s) {
+    int more, i = 0;
+    unsigned leb = 0;
+
+    do {
+        int byte = get_bits(s, 8);
+        unsigned bits = byte & 0x7f;
+        more = byte & 0x80;
+        if (i <= 4)
+            leb |= bits << (i * 7);
+        if (++i == 8)
+            break;
+    } while (more);
+
+    return leb;
+}
+
+/**
+ * Read a unsigned integer coded as a variable number of up to eight
+ * little-endian bytes, where the MSB in a byte signals another byte
+ * must be read.
+ */
+static inline int64_t get_leb128(GetBitContext *gb) {
+    int64_t ret = 0;
+
+    for (int i = 0; i < 8; i++) {
+        int byte = get_bits(gb, 8);
+        ret |= (int64_t)(byte & 0x7f) << (i * 7);
+        if (!(byte & 0x80))
+            break;
+    }
+
+    return ret;
+}
+
+#endif /* AVCODEC_LEB_H */

libavformat/av1dec.c

@@ -325,7 +325,7 @@ static int read_obu_with_size(const uint8_t *buf, int buf_size, int64_t *obu_siz
         skip_bits(&gb, 3);  // extension_header_reserved_3bits
     }
 
-    *obu_size  = leb128(&gb);
+    *obu_size  = get_leb128(&gb);
     if (*obu_size > INT_MAX)
         return AVERROR_INVALIDDATA;
 

libavformat/iamf_parse.c

@@ -26,6 +26,7 @@
 #include "libavutil/log.h"
 #include "libavcodec/get_bits.h"
 #include "libavcodec/flac.h"
+#include "libavcodec/leb.h"
 #include "libavcodec/mpeg4audio.h"
 #include "libavcodec/put_bits.h"
 #include "avio_internal.h"