avcodec/put_bits: Add and use put_bits63()

When using a 64bit PutBitContext (i.e. on x64), put_bits_no_assert()
can naturally write up to 63 bits. So one can avoid treating the
cases <32bits, 32 bits and <63 bits differently.

As it turns out, no user actually wants to write 64 bit at once
(maybe except testprograms).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/dovi_rpuenc.c

@@ -334,12 +334,12 @@ static inline void put_ue_coef(PutBitContext *pb, const AVDOVIRpuDataHeader *hdr
     switch (hdr->coef_data_type) {
     case RPU_COEFF_FIXED:
         set_ue_golomb(pb, coef >> hdr->coef_log2_denom);
-        put_bits64(pb, hdr->coef_log2_denom,
+        put_bits63(pb, hdr->coef_log2_denom,
                    coef & ((1LL << hdr->coef_log2_denom) - 1));
         break;
     case RPU_COEFF_FLOAT:
         fpart.f32 = coef / (float) (1LL << hdr->coef_log2_denom);
-        put_bits64(pb, hdr->coef_log2_denom, fpart.u32);
+        put_bits63(pb, hdr->coef_log2_denom, fpart.u32);
         break;
     }
 }
@@ -352,12 +352,12 @@ static inline void put_se_coef(PutBitContext *pb, const AVDOVIRpuDataHeader *hdr
     switch (hdr->coef_data_type) {
     case RPU_COEFF_FIXED:
         set_se_golomb(pb, coef >> hdr->coef_log2_denom);
-        put_bits64(pb, hdr->coef_log2_denom,
+        put_bits63(pb, hdr->coef_log2_denom,
                    coef & ((1LL << hdr->coef_log2_denom) - 1));
         break;
     case RPU_COEFF_FLOAT:
         fpart.f32 = coef / (float) (1LL << hdr->coef_log2_denom);
-        put_bits64(pb, hdr->coef_log2_denom, fpart.u32);
+        put_bits63(pb, hdr->coef_log2_denom, fpart.u32);
         break;
     }
 }

libavcodec/put_bits.h

@@ -39,14 +39,14 @@
 typedef uint64_t BitBuf;
 #define AV_WBBUF AV_WB64
 #define AV_WLBUF AV_WL64
+#define BUF_BITS 64
 #else
 typedef uint32_t BitBuf;
 #define AV_WBBUF AV_WB32
 #define AV_WLBUF AV_WL32
+#define BUF_BITS 32
 #endif
 
-static const int BUF_BITS = 8 * sizeof(BitBuf);
-
 typedef struct PutBitContext {
     BitBuf bit_buf;
     int bit_left;
@@ -329,12 +329,15 @@ static void av_unused put_bits32(PutBitContext *s, uint32_t value)
 }
 
 /**
- * Write up to 64 bits into a bitstream.
+ * Write up to 63 bits into a bitstream.
  */
-static inline void put_bits64(PutBitContext *s, int n, uint64_t value)
+static inline void put_bits63(PutBitContext *s, int n, uint64_t value)
 {
-    av_assert2((n == 64) || (n < 64 && value < (UINT64_C(1) << n)));
+    av_assert2(n < 64U && value < (UINT64_C(1) << n));
 
+#if BUF_BITS >= 64
+    put_bits_no_assert(s, n, value);
+#else
     if (n < 32)
         put_bits(s, n, value);
     else if (n == 32)
@@ -349,6 +352,19 @@ static inline void put_bits64(PutBitContext *s, int n, uint64_t value)
         put_bits(s, n - 32, hi);
         put_bits32(s, lo);
 #endif
+    }
+#endif
+}
+
+/**
+ * Write up to 64 bits into a bitstream.
+ */
+static inline void put_bits64(PutBitContext *s, int n, uint64_t value)
+{
+    av_assert2((n == 64) || (n < 64 && value < (UINT64_C(1) << n)));
+
+    if (n < 64) {
+        put_bits63(s, n, value);
     } else {
         uint32_t lo = value & 0xffffffff;
         uint32_t hi = value >> 32;
@@ -359,7 +375,6 @@ static inline void put_bits64(PutBitContext *s, int n, uint64_t value)
         put_bits32(s, hi);
         put_bits32(s, lo);
 #endif
-
     }
 }
 
@@ -367,7 +382,7 @@ static inline void put_sbits63(PutBitContext *pb, int n, int64_t value)
 {
     av_assert2(n >= 0 && n < 64);
 
-    put_bits64(pb, n, (uint64_t)(value) & (~(UINT64_MAX << n)));
+    put_bits63(pb, n, (uint64_t)(value) & (~(UINT64_MAX << n)));
 }
 
 /**

libavcodec/put_golomb.h

@@ -62,7 +62,7 @@ static inline void set_ue_golomb_long(PutBitContext *pb, uint32_t i)
         put_bits(pb, ff_ue_golomb_len[i], i + 1);
     else {
         int e = av_log2(i + 1);
-        put_bits64(pb, 2 * e + 1, i + 1);
+        put_bits63(pb, 2 * e + 1, i + 1);
     }
 }
 

libavcodec/vc2enc.c

@@ -201,7 +201,7 @@ static av_always_inline void put_vc2_ue_uint(PutBitContext *pb, uint32_t val)
             pbits |= 0x1;
     }
 
-    put_bits64(pb, bits*2 + 1, (pbits << 1) | 1);
+    put_bits63(pb, 2 * bits + 1, (pbits << 1) | 1);
 }
 
 static av_always_inline int count_vc2_ue_uint(uint32_t val)

libavformat/iamf_parse.c

@@ -319,7 +319,7 @@ static int update_extradata(AVCodecParameters *codecpar)
             return ret;
 
         put_bits32(&pb, get_bits_long(&gb, 32)); // min/max blocksize
-        put_bits64(&pb, 48, get_bits64(&gb, 48)); // min/max framesize
+        put_bits63(&pb, 48, get_bits64(&gb, 48)); // min/max framesize
         put_bits(&pb, 20, get_bits(&gb, 20)); // samplerate
         skip_bits(&gb, 3);
         put_bits(&pb, 3, codecpar->ch_layout.nb_channels - 1);

libavformat/iamf_writer.c

@@ -59,7 +59,7 @@ static int update_extradata(IAMFCodecConfig *codec_config)
             return ret;
 
         put_bits32(&pb, get_bits_long(&gb, 32)); // min/max blocksize
-        put_bits64(&pb, 48, get_bits64(&gb, 48)); // min/max framesize
+        put_bits63(&pb, 48, get_bits64(&gb, 48)); // min/max framesize
         put_bits(&pb, 20, get_bits(&gb, 20)); // samplerate
         skip_bits(&gb, 3);
         put_bits(&pb, 3, 1); // set channels to stereo