X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fput_bits.h;h=689c6b282ef50b95229944cf5f6b00b65a606c69;hb=bd96c54fe4819b3ca9a975e2083d67f4443c559b;hp=1ceb1cc766246dff19de5d7baf97a5c79a3bc157;hpb=94d98330ed6c5562341315c26c1af92771a2e6de;p=ffmpeg

diff --git a/libavcodec/put_bits.h b/libavcodec/put_bits.h
index 1ceb1cc7662..689c6b282ef 100644
--- a/libavcodec/put_bits.h
+++ b/libavcodec/put_bits.h
@@ -29,14 +29,27 @@
 #include <stdint.h>
 #include <stddef.h>
 
+#include "config.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/avassert.h"
 
+#if ARCH_X86_64
+// TODO: Benchmark and optionally enable on other 64-bit architectures.
+typedef uint64_t BitBuf;
+#define AV_WBBUF AV_WB64
+#define AV_WLBUF AV_WL64
+#else
+typedef uint32_t BitBuf;
+#define AV_WBBUF AV_WB32
+#define AV_WLBUF AV_WL32
+#endif
+
+static const int BUF_BITS = 8 * sizeof(BitBuf);
+
 typedef struct PutBitContext {
-    uint32_t bit_buf;
+    BitBuf bit_buf;
     int bit_left;
     uint8_t *buf, *buf_ptr, *buf_end;
-    int size_in_bits;
 } PutBitContext;
 
 /**
@@ -53,46 +66,74 @@ static inline void init_put_bits(PutBitContext *s, uint8_t *buffer,
         buffer      = NULL;
     }
 
-    s->size_in_bits = 8 * buffer_size;
     s->buf          = buffer;
     s->buf_end      = s->buf + buffer_size;
     s->buf_ptr      = s->buf;
-    s->bit_left     = 32;
+    s->bit_left     = BUF_BITS;
     s->bit_buf      = 0;
 }
 
+/**
+ * @return the total number of bits written to the bitstream.
+ */
+static inline int put_bits_count(PutBitContext *s)
+{
+    return (s->buf_ptr - s->buf) * 8 + BUF_BITS - s->bit_left;
+}
+
+/**
+ * @return the number of bytes output so far; may only be called
+ *         when the PutBitContext is freshly initialized or flushed.
+ */
+static inline int put_bytes_output(const PutBitContext *s)
+{
+    av_assert2(s->bit_left == BUF_BITS);
+    return s->buf_ptr - s->buf;
+}
+
+/**
+ * @param  round_up  When set, the number of bits written so far will be
+ *                   rounded up to the next byte.
+ * @return the number of bytes output so far.
+ */
+static inline int put_bytes_count(const PutBitContext *s, int round_up)
+{
+    return s->buf_ptr - s->buf + ((BUF_BITS - s->bit_left + (round_up ? 7 : 0)) >> 3);
+}
+
 /**
  * Rebase the bit writer onto a reallocated buffer.
  *
  * @param buffer the buffer where to put bits
  * @param buffer_size the size in bytes of buffer,
- *                    must be larger than the previous size
+ *                    must be large enough to hold everything written so far
  */
 static inline void rebase_put_bits(PutBitContext *s, uint8_t *buffer,
                                    int buffer_size)
 {
-    av_assert0(8*buffer_size > s->size_in_bits);
+    av_assert0(8*buffer_size >= put_bits_count(s));
 
     s->buf_end = buffer + buffer_size;
     s->buf_ptr = buffer + (s->buf_ptr - s->buf);
     s->buf     = buffer;
-    s->size_in_bits = 8 * buffer_size;
 }
 
 /**
- * @return the total number of bits written to the bitstream.
+ * @return the number of bits available in the bitstream.
  */
-static inline int put_bits_count(PutBitContext *s)
+static inline int put_bits_left(PutBitContext* s)
 {
-    return (s->buf_ptr - s->buf) * 8 + 32 - s->bit_left;
+    return (s->buf_end - s->buf_ptr) * 8 - BUF_BITS + s->bit_left;
 }
 
 /**
- * @return the number of bits available in the bitstream.
+ * @param  round_up  When set, the number of bits written will be
+ *                   rounded up to the next byte.
+ * @return the number of bytes left.
  */
-static inline int put_bits_left(PutBitContext* s)
+static inline int put_bytes_left(const PutBitContext *s, int round_up)
 {
-    return (s->buf_end - s->buf_ptr) * 8 - 32 + s->bit_left;
+    return s->buf_end - s->buf_ptr - ((BUF_BITS - s->bit_left + (round_up ? 7 : 0)) >> 3);
 }
 
 /**
@@ -101,52 +142,47 @@ static inline int put_bits_left(PutBitContext* s)
 static inline void flush_put_bits(PutBitContext *s)
 {
 #ifndef BITSTREAM_WRITER_LE
-    if (s->bit_left < 32)
+    if (s->bit_left < BUF_BITS)
         s->bit_buf <<= s->bit_left;
 #endif
-    while (s->bit_left < 32) {
+    while (s->bit_left < BUF_BITS) {
         av_assert0(s->buf_ptr < s->buf_end);
 #ifdef BITSTREAM_WRITER_LE
         *s->buf_ptr++ = s->bit_buf;
         s->bit_buf  >>= 8;
 #else
-        *s->buf_ptr++ = s->bit_buf >> 24;
+        *s->buf_ptr++ = s->bit_buf >> (BUF_BITS - 8);
         s->bit_buf  <<= 8;
 #endif
         s->bit_left  += 8;
     }
-    s->bit_left = 32;
+    s->bit_left = BUF_BITS;
     s->bit_buf  = 0;
 }
 
 static inline void flush_put_bits_le(PutBitContext *s)
 {
-    while (s->bit_left < 32) {
+    while (s->bit_left < BUF_BITS) {
         av_assert0(s->buf_ptr < s->buf_end);
         *s->buf_ptr++ = s->bit_buf;
         s->bit_buf  >>= 8;
         s->bit_left  += 8;
     }
-    s->bit_left = 32;
+    s->bit_left = BUF_BITS;
     s->bit_buf  = 0;
 }
 
 #ifdef BITSTREAM_WRITER_LE
-#define avpriv_align_put_bits align_put_bits_unsupported_here
-#define avpriv_put_string ff_put_string_unsupported_here
-#define avpriv_copy_bits avpriv_copy_bits_unsupported_here
+#define ff_put_string ff_put_string_unsupported_here
+#define ff_copy_bits ff_copy_bits_unsupported_here
 #else
-/**
- * Pad the bitstream with zeros up to the next byte boundary.
- */
-void avpriv_align_put_bits(PutBitContext *s);
 
 /**
  * Put the string string in the bitstream.
  *
  * @param terminate_string 0-terminates the written string if value is 1
  */
-void avpriv_put_string(PutBitContext *pb, const char *string,
+void ff_put_string(PutBitContext *pb, const char *string,
                        int terminate_string);
 
 /**
@@ -154,36 +190,30 @@ void avpriv_put_string(PutBitContext *pb, const char *string,
  *
  * @param length the number of bits of src to copy
  */
-void avpriv_copy_bits(PutBitContext *pb, const uint8_t *src, int length);
+void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length);
 #endif
 
-/**
- * Write up to 31 bits into a bitstream.
- * Use put_bits32 to write 32 bits.
- */
-static inline void put_bits(PutBitContext *s, int n, unsigned int value)
+static inline void put_bits_no_assert(PutBitContext *s, int n, BitBuf value)
 {
-    unsigned int bit_buf;
+    BitBuf bit_buf;
     int bit_left;
 
-    av_assert2(n <= 31 && value < (1U << n));
-
     bit_buf  = s->bit_buf;
     bit_left = s->bit_left;
 
     /* XXX: optimize */
 #ifdef BITSTREAM_WRITER_LE
-    bit_buf |= value << (32 - bit_left);
+    bit_buf |= value << (BUF_BITS - bit_left);
     if (n >= bit_left) {
-        if (3 < s->buf_end - s->buf_ptr) {
-            AV_WL32(s->buf_ptr, bit_buf);
-            s->buf_ptr += 4;
+        if (s->buf_end - s->buf_ptr >= sizeof(BitBuf)) {
+            AV_WLBUF(s->buf_ptr, bit_buf);
+            s->buf_ptr += sizeof(BitBuf);
         } else {
             av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n");
             av_assert2(0);
         }
         bit_buf     = value >> bit_left;
-        bit_left   += 32;
+        bit_left   += BUF_BITS;
     }
     bit_left -= n;
 #else
@@ -193,14 +223,14 @@ static inline void put_bits(PutBitContext *s, int n, unsigned int value)
     } else {
         bit_buf   <<= bit_left;
         bit_buf    |= value >> (n - bit_left);
-        if (3 < s->buf_end - s->buf_ptr) {
-            AV_WB32(s->buf_ptr, bit_buf);
-            s->buf_ptr += 4;
+        if (s->buf_end - s->buf_ptr >= sizeof(BitBuf)) {
+            AV_WBBUF(s->buf_ptr, bit_buf);
+            s->buf_ptr += sizeof(BitBuf);
         } else {
             av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n");
             av_assert2(0);
         }
-        bit_left   += 32 - n;
+        bit_left   += BUF_BITS - n;
         bit_buf     = value;
     }
 #endif
@@ -209,27 +239,37 @@ static inline void put_bits(PutBitContext *s, int n, unsigned int value)
     s->bit_left = bit_left;
 }
 
-static inline void put_bits_le(PutBitContext *s, int n, unsigned int value)
+/**
+ * Write up to 31 bits into a bitstream.
+ * Use put_bits32 to write 32 bits.
+ */
+static inline void put_bits(PutBitContext *s, int n, BitBuf value)
 {
-    unsigned int bit_buf;
+    av_assert2(n <= 31 && value < (1UL << n));
+    put_bits_no_assert(s, n, value);
+}
+
+static inline void put_bits_le(PutBitContext *s, int n, BitBuf value)
+{
+    BitBuf bit_buf;
     int bit_left;
 
-    av_assert2(n <= 31 && value < (1U << n));
+    av_assert2(n <= 31 && value < (1UL << n));
 
     bit_buf  = s->bit_buf;
     bit_left = s->bit_left;
 
-    bit_buf |= value << (32 - bit_left);
+    bit_buf |= value << (BUF_BITS - bit_left);
     if (n >= bit_left) {
-        if (3 < s->buf_end - s->buf_ptr) {
-            AV_WL32(s->buf_ptr, bit_buf);
-            s->buf_ptr += 4;
+        if (s->buf_end - s->buf_ptr >= sizeof(BitBuf)) {
+            AV_WLBUF(s->buf_ptr, bit_buf);
+            s->buf_ptr += sizeof(BitBuf);
         } else {
             av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n");
             av_assert2(0);
         }
         bit_buf     = value >> bit_left;
-        bit_left   += 32;
+        bit_left   += BUF_BITS;
     }
     bit_left -= n;
 
@@ -249,17 +289,22 @@ static inline void put_sbits(PutBitContext *pb, int n, int32_t value)
  */
 static void av_unused put_bits32(PutBitContext *s, uint32_t value)
 {
-    unsigned int bit_buf;
+    BitBuf bit_buf;
     int bit_left;
 
+    if (BUF_BITS > 32) {
+        put_bits_no_assert(s, 32, value);
+        return;
+    }
+
     bit_buf  = s->bit_buf;
     bit_left = s->bit_left;
 
 #ifdef BITSTREAM_WRITER_LE
-    bit_buf |= value << (32 - bit_left);
-    if (3 < s->buf_end - s->buf_ptr) {
-        AV_WL32(s->buf_ptr, bit_buf);
-        s->buf_ptr += 4;
+    bit_buf |= (BitBuf)value << (BUF_BITS - bit_left);
+    if (s->buf_end - s->buf_ptr >= sizeof(BitBuf)) {
+        AV_WLBUF(s->buf_ptr, bit_buf);
+        s->buf_ptr += sizeof(BitBuf);
     } else {
         av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n");
         av_assert2(0);
@@ -267,10 +312,10 @@ static void av_unused put_bits32(PutBitContext *s, uint32_t value)
     bit_buf     = (uint64_t)value >> bit_left;
 #else
     bit_buf     = (uint64_t)bit_buf << bit_left;
-    bit_buf    |= value >> (32 - bit_left);
-    if (3 < s->buf_end - s->buf_ptr) {
-        AV_WB32(s->buf_ptr, bit_buf);
-        s->buf_ptr += 4;
+    bit_buf    |= (BitBuf)value >> (BUF_BITS - bit_left);
+    if (s->buf_end - s->buf_ptr >= sizeof(BitBuf)) {
+        AV_WBBUF(s->buf_ptr, bit_buf);
+        s->buf_ptr += sizeof(BitBuf);
     } else {
         av_log(NULL, AV_LOG_ERROR, "Internal error, put_bits buffer too small\n");
         av_assert2(0);
@@ -333,7 +378,7 @@ static inline uint8_t *put_bits_ptr(PutBitContext *s)
 static inline void skip_put_bytes(PutBitContext *s, int n)
 {
     av_assert2((put_bits_count(s) & 7) == 0);
-    av_assert2(s->bit_left == 32);
+    av_assert2(s->bit_left == BUF_BITS);
     av_assert0(n <= s->buf_end - s->buf_ptr);
     s->buf_ptr += n;
 }
@@ -341,13 +386,13 @@ static inline void skip_put_bytes(PutBitContext *s, int n)
 /**
  * Skip the given number of bits.
  * Must only be used if the actual values in the bitstream do not matter.
- * If n is 0 the behavior is undefined.
+ * If n is < 0 the behavior is undefined.
  */
 static inline void skip_put_bits(PutBitContext *s, int n)
 {
-    s->bit_left -= n;
-    s->buf_ptr  -= 4 * (s->bit_left >> 5);
-    s->bit_left &= 31;
+    unsigned bits = BUF_BITS - s->bit_left + n;
+    s->buf_ptr += sizeof(BitBuf) * (bits / BUF_BITS);
+    s->bit_left = BUF_BITS - (bits & (BUF_BITS - 1));
 }
 
 /**
@@ -357,9 +402,19 @@ static inline void skip_put_bits(PutBitContext *s, int n)
  */
 static inline void set_put_bits_buffer_size(PutBitContext *s, int size)
 {
-    av_assert0(size <= INT_MAX/8 - 32);
+    av_assert0(size <= INT_MAX/8 - BUF_BITS);
     s->buf_end = s->buf + size;
-    s->size_in_bits = 8*size;
 }
 
+/**
+ * Pad the bitstream with zeros up to the next byte boundary.
+ */
+static inline void align_put_bits(PutBitContext *s)
+{
+    put_bits(s, s->bit_left & 7, 0);
+}
+
+#undef AV_WBBUF
+#undef AV_WLBUF
+
 #endif /* AVCODEC_PUT_BITS_H */