[Bug c/60902] New: ffmpeg built with gcc 4.9 RC produces incorrect flac playback code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60902 Bug ID: 60902 Summary: ffmpeg built with gcc 4.9 RC produces incorrect flac playback code Product: gcc Version: 4.9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: arthur.marsh at internode dot on.net Using the gcc-4.9 version 4.9-20140411-2 on Debian GNU/Linux amd64, I'm getting incorrect code for ffmpeg flac format decoding (same source code compiled with gcc-4.8 version 4.8.2-19 works fine). The problem only affects some flac files that have nonetheless been passed as valid by flac version 1.3.0. The error returned is similar to: [flac @ 0x7f3b540092e0] invalid subframe paddingB sq=0B f=0/0 [flac @ 0x7f3b540092e0] decode_frame() failed The bug report against ffmpeg is at: https://trac.ffmpeg.org/ticket/3559 I am *NOT* a C programmer and am not familiar with the flac format decoding process but am posting this in case anyone who is might be prepared to investigate further. Thanks for any help or suggestions.
[Bug target/60902] ffmpeg built with gcc 4.9 RC produces incorrect flac playback code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60902 --- Comment #2 from Arthur Marsh --- Created attachment 32637 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32637&action=edit config.mak produced by ./configure --cc=gcc-4.9 --host-cc=gcc-4.9 --dep-cc=gcc-4.9
[Bug target/60902] ffmpeg built with gcc 4.9 RC produces incorrect flac playback code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60902 --- Comment #3 from Arthur Marsh --- I've attached the config.mak produced by ./configure --cc=gcc-4.9 --host-cc=gcc-4.9 --dep-cc=gcc-4.9 The CFLAGS from config.mak: CFLAGS= -std=c99 -fomit-frame-pointer -pthread -D_GNU_SOURCE=1 -D_REENTRANT -I /usr/include/SDL -g -Wdeclaration-after-statement -Wall -Wdisabled-optimization -Wpointer-arith -Wredundant-decls -Wwrite-strings -Wtype-limits -Wundef -missing-prototypes -Wno-pointer-to-int-cast -Wstrict-prototypes -Wempty-body -Wno-parentheses -Wno-switch -Wno-format-zero-length -Wno-pointer-sign -O3 -fno-math-errno -fno-signed-zeros -fno-tree-vectorize -Werror=implicit-function-declaration -Werror=missing-prototypes -Werror=return-type -Werror=vla -Wno-maybe-uninitialized
[Bug target/60902] ffmpeg built with gcc 4.9 RC produces incorrect flac playback code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60902 --- Comment #4 from Arthur Marsh --- I've attached the config.mak produced by ./configure --cc=gcc-4.9 --host-cc=gcc-4.9 --dep-cc=gcc-4.9 The CFLAGS from config.mak: CFLAGS= -std=c99 -fomit-frame-pointer -pthread -D_GNU_SOURCE=1 -D_REENTRANT -I /usr/include/SDL -g -Wdeclaration-after-statement -Wall -Wdisabled-optimization -Wpointer-arith -Wredundant-decls -Wwrite-strings -Wtype-limits -Wundef -missing-prototypes -Wno-pointer-to-int-cast -Wstrict-prototypes -Wempty-body -Wno-parentheses -Wno-switch -Wno-format-zero-length -Wno-pointer-sign -O3 -fno-math-errno -fno-signed-zeros -fno-tree-vectorize -Werror=implicit-function-declaration -Werror=missing-prototypes -Werror=return-type -Werror=vla -Wno-maybe-uninitialized
[Bug target/60902] ffmpeg built with gcc 4.9 RC produces incorrect flac playback code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60902 --- Comment #7 from Arthur Marsh --- OK, I modified the CFLAGS statement in config.mak to what is below, re-ran make clean and make, and still experienced the same problems. CFLAGS= -std=c99 -fomit-frame-pointer -pthread -D_GNU_SOURCE=1 -D_REENTRANT -I/usr/include/SDL -g -Wdeclaration-after-statement -Wall -Wdisabled-optimization -Wpointer-arith -Wredundant-decls -Wwrite-strings -Wtype-limits -Wundef -Wmissing-prototypes -Wno-pointer-to-int-cast -Wstrict-prototypes -Wempty-body -Wno-parentheses -Wno-switch -Wno-format-zero-length -Wno-pointer-sign -O3 -fno-math-errno -fno-signed-zeros -fno-tree-vectorize -Werror=implicit-function-declaration -Werror=missing-prototypes -Werror=return-type -Werror=vla -Wno-maybe-uninitialized -fno-strict-aliasing -fwrapv -fno-aggressive-loop-optimizations Thanks for your interest.
[Bug target/60902] ffmpeg built with gcc 4.9 RC produces incorrect flac playback code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60902 --- Comment #8 from Arthur Marsh --- PS, no assembly language in the flac decoding process as far as I could see.
[Bug target/60902] ffmpeg built with gcc 4.9 RC produces incorrect flac playback code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60902 --- Comment #10 from Arthur Marsh --- I haven't been able to reproduce what was shown in comment 9, but appreciate the effort taken to reproduce the problem.
