diff --git a/configure b/configure
index f73f7850c0785f7c0e6d592063112117df770687..c5c89aa6cf7e560b4828fa75ad27a6421548d635 100755
--- a/configure
+++ b/configure
@@ -4000,24 +4000,6 @@ armasm_flags(){
    done
 }
 
-ccc_flags(){
-    for flag; do
-        case $flag in
-            -std=c99)           echo -c99                       ;;
-            -mcpu=*)            echo -arch ${flag#*=}           ;;
-            -mieee)             echo -ieee                      ;;
-            -O*|-fast)          echo $flag                      ;;
-            -fno-math-errno)    echo -assume nomath_errno       ;;
-            -g)                 echo -g3                        ;;
-            -Wall)              echo -msg_enable level2         ;;
-            -Wno-pointer-sign)  echo -msg_disable ptrmismatch1  ;;
-            -Wl,*)              echo $flag                      ;;
-            -f*|-W*)                                            ;;
-            *)                  echo $flag                      ;;
-        esac
-   done
-}
-
 cparser_flags(){
     for flag; do
         case $flag in
@@ -4232,13 +4214,6 @@ probe_cc(){
         _ident=$($_cc -qversion 2>/dev/null | head -n1)
         _cflags_speed='-O5'
         _cflags_size='-O5 -qcompact'
-    elif $_cc -V 2>/dev/null | grep -q Compaq; then
-        _type=ccc
-        _ident=$($_cc -V | head -n1 | cut -d' ' -f1-3)
-        _DEPFLAGS='-M'
-        _cflags_speed='-fast'
-        _cflags_size='-O1'
-        _flags_filter=ccc_flags
     elif $_cc --vsn 2>/dev/null | grep -Eq "ARM (C/C\+\+ )?Compiler"; then
         test -d "$sysroot" || die "No valid sysroot specified."
         _type=armcc
@@ -5183,9 +5158,6 @@ case $target_os in
                       -l:drtaeabi.dso -l:scppnwdl.dso -lsupc++ -lgcc \
                       -l:libc.dso -l:libm.dso -l:euser.dso -l:libcrt0.lib
         ;;
-    osf1)
-        add_cppflags -D_OSF_SOURCE -D_POSIX_PII -D_REENTRANT
-        ;;
     minix)
         ;;
     none)
@@ -5327,8 +5299,6 @@ case $libc_type in
             add_cppflags -D__builtin_memset=memset
             add_cppflags -D__gnuc_va_list=va_list -D_VA_LIST_DEFINED
             add_cflags   -pds=48    # incompatible redefinition of macro
-        elif enabled ccc; then
-            add_ldflags -Wl,-z,now  # calls to libots crash without this
         fi
         ;;
 esac
@@ -6507,12 +6477,6 @@ if enabled icc; then
             check_cflags -falign-stack=maintain-16-byte ||
             disable aligned_stack
     fi
-elif enabled ccc; then
-    # disable some annoying warnings
-    add_cflags -msg_disable bitnotint
-    add_cflags -msg_disable mixfuncvoid
-    add_cflags -msg_disable nonstandcast
-    add_cflags -msg_disable unsupieee
 elif enabled gcc; then
     check_optflags -fno-tree-vectorize
     check_cflags -Werror=format-security
@@ -6611,12 +6575,6 @@ case $ld_type in
     ;;
 esac
 
-case $target_os in
-    osf1)
-        enabled ccc && add_ldflags '-Wl,-expect_unresolved,*'
-    ;;
-esac
-
 enable frame_thread_encoder
 
 enabled asm || { arch=c; disable $ARCH_LIST $ARCH_EXT_LIST; }
diff --git a/libavcodec/alpha/asm.h b/libavcodec/alpha/asm.h
index 827721e777fc161f18d5d249290c9838065334da..6d850cecc640b4577ff87e57f0b59738bcbe335c 100644
--- a/libavcodec/alpha/asm.h
+++ b/libavcodec/alpha/asm.h
@@ -146,39 +146,6 @@ struct unaligned_long { uint64_t l; } __attribute__((packed));
 #define unpkbw(a)    ({ uint64_t __r; __asm__ (".arch ev6; unpkbw  %r1,%0"     : "=r" (__r) : "rJ"  (a));           __r; })
 #endif
 
-#elif defined(__DECC)           /* Digital/Compaq/hp "ccc" compiler */
-
-#include <c_asm.h>
-#define ldq(p) (*(const uint64_t *) (p))
-#define ldl(p) (*(const int32_t *)  (p))
-#define stq(l, p) do { *(uint64_t *) (p) = (l); } while (0)
-#define stl(l, p) do { *(int32_t *)  (p) = (l); } while (0)
-#define ldq_u(a)     asm ("ldq_u   %v0,0(%a0)", a)
-#define uldq(a)      (*(const __unaligned uint64_t *) (a))
-#define cmpbge(a, b) asm ("cmpbge  %a0,%a1,%v0", a, b)
-#define extql(a, b)  asm ("extql   %a0,%a1,%v0", a, b)
-#define extwl(a, b)  asm ("extwl   %a0,%a1,%v0", a, b)
-#define extqh(a, b)  asm ("extqh   %a0,%a1,%v0", a, b)
-#define zap(a, b)    asm ("zap     %a0,%a1,%v0", a, b)
-#define zapnot(a, b) asm ("zapnot  %a0,%a1,%v0", a, b)
-#define amask(a)     asm ("amask   %a0,%v0", a)
-#define implver()    asm ("implver %v0")
-#define rpcc()       asm ("rpcc           %v0")
-#define minub8(a, b) asm ("minub8  %a0,%a1,%v0", a, b)
-#define minsb8(a, b) asm ("minsb8  %a0,%a1,%v0", a, b)
-#define minuw4(a, b) asm ("minuw4  %a0,%a1,%v0", a, b)
-#define minsw4(a, b) asm ("minsw4  %a0,%a1,%v0", a, b)
-#define maxub8(a, b) asm ("maxub8  %a0,%a1,%v0", a, b)
-#define maxsb8(a, b) asm ("maxsb8  %a0,%a1,%v0", a, b)
-#define maxuw4(a, b) asm ("maxuw4  %a0,%a1,%v0", a, b)
-#define maxsw4(a, b) asm ("maxsw4  %a0,%a1,%v0", a, b)
-#define perr(a, b)   asm ("perr    %a0,%a1,%v0", a, b)
-#define pklb(a)      asm ("pklb    %a0,%v0", a)
-#define pkwb(a)      asm ("pkwb    %a0,%v0", a)
-#define unpkbl(a)    asm ("unpkbl  %a0,%v0", a)
-#define unpkbw(a)    asm ("unpkbw  %a0,%v0", a)
-#define wh64(a)      asm ("wh64    %a0", a)
-
 #else
 #error "Unknown compiler!"
 #endif
diff --git a/libavutil/intreadwrite.h b/libavutil/intreadwrite.h
index d54d4b91d6ce9543cc23b4849f3a6f600650ae47..5b4094e6bcd69ccbb691c374c497c7d567d7a4f1 100644
--- a/libavutil/intreadwrite.h
+++ b/libavutil/intreadwrite.h
@@ -224,11 +224,6 @@ union unaligned_16 { uint16_t l; } __attribute__((packed)) av_alias;
 #   define AV_RN(s, p) (((const union unaligned_##s *) (p))->l)
 #   define AV_WN(s, p, v) ((((union unaligned_##s *) (p))->l) = (v))
 
-#elif defined(__DECC)
-
-#   define AV_RN(s, p) (*((const __unaligned uint##s##_t*)(p)))
-#   define AV_WN(s, p, v) (*((__unaligned uint##s##_t*)(p)) = (v))
-
 #elif defined(_MSC_VER) && (defined(_M_ARM) || defined(_M_X64)) && AV_HAVE_FAST_UNALIGNED
 
 #   define AV_RN(s, p) (*((const __unaligned uint##s##_t*)(p)))