> 2021年12月5日 下午6:56，Andreas Rheinhardt <andreas.rheinha...@outlook.com> 写道： > > Yu Yang: >> Opts is assigned by setup_find_stream_info_opts(). Could not get opts when >> nb_streams == 0. >> It should not return NULL but print AV_LOG_ERROR. when no alloc memory for >> stream options, >> it also need return an error to avoid crash when free. In total, >> setup_find_stream_info_opts() >> should not return NULL. It print AV_LOG_ERROR or correct value. >> >> coredump backtrace info: >> ==6235==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc >> 0x000006ba9c2f bp 0x7ffc3d5baa30 sp 0x7ffc3d5ba9a0 T0) >> ==6235==The signal is caused by a READ memory access. >> ==6235==Hint: address points to the zero page. >> #0 0x6ba9c2f in av_dict_free >> /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavutil/dict.c:205:23 >> #1 0x4ce5ac in open_input_file >> /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg_opt.c:1199:13 >> #2 0x4c9dc0 in open_files >> /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg_opt.c:3338:15 >> #3 0x4c9295 in ffmpeg_parse_options >> /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg_opt.c:3378:11 >> #4 0x58f241 in main >> /home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg.c:4988:11 >> #5 0x7fe35197f0b2 in __libc_start_main >> /build/glibc-eX1tMB/glibc-2.31/csu/../csu/libc-start.c:308:16 >> #6 0x42033d in _start (/home/r1/ffmpeg/ffmpeg_4.4.1+0x42033d) >> >> Reported-by: TOTE Robot <os...@tsinghua.edu.cn> >> Signed-off-by: Yu Yang <young_chel...@163.com> >> --- >> fftools/cmdutils.c | 6 ++++-- >> libavformat/demux.c | 12 +++++------- >> 2 files changed, 9 insertions(+), 9 deletions(-) >> >> diff --git a/fftools/cmdutils.c b/fftools/cmdutils.c >> index 45322f8c71..f4333d8b65 100644 >> --- a/fftools/cmdutils.c >> +++ b/fftools/cmdutils.c >> @@ -2182,12 +2182,14 @@ AVDictionary >> **setup_find_stream_info_opts(AVFormatContext *s, >> AVDictionary **opts; >> >> if (!s->nb_streams) >> - return NULL; >> + av_log(NULL, AV_LOG_ERROR, >> + "No stream exists, Could not get stream options.\n"); >> + exit_program(1); > > This is completely wrong: You are unconditionally exiting the program > (the indentation here is now misleading). Had you run FATE (see > https://ffmpeg.org/fate.html), you would have noticed this. I forgot to run 'make fate'. > Exiting the program in case of no streams is wrong, too. OK, got it. > >> opts = av_calloc(s->nb_streams, sizeof(*opts)); >> if (!opts) { >> av_log(NULL, AV_LOG_ERROR, >> "Could not alloc memory for stream options.\n"); >> - return NULL; >> + exit_program(1); >> } >> for (i = 0; i < s->nb_streams; i++) >> opts[i] = filter_codec_opts(codec_opts, >> s->streams[i]->codecpar->codec_id, >> diff --git a/libavformat/demux.c b/libavformat/demux.c >> index 745dc8687c..0738ef2e73 100644 >> --- a/libavformat/demux.c >> +++ b/libavformat/demux.c >> @@ -2434,7 +2434,7 @@ int avformat_find_stream_info(AVFormatContext *ic, >> AVDictionary **options) >> >> for (unsigned i = 0; i < ic->nb_streams; i++) { >> const AVCodec *codec; >> - AVDictionary *thread_opt = NULL; >> + >> AVStream *const st = ic->streams[i]; >> FFStream *const sti = ffstream(st); >> AVCodecContext *const avctx = sti->avctx; >> @@ -2474,26 +2474,24 @@ int avformat_find_stream_info(AVFormatContext *ic, >> AVDictionary **options) >> >> /* Force thread count to 1 since the H.264 decoder will not extract >> * SPS and PPS to extradata during multi-threaded decoding. */ >> - av_dict_set(options ? &options[i] : &thread_opt, "threads", "1", 0); >> + av_dict_set(&options[i], "threads", "1", 0); >> /* Force lowres to 0. The decoder might reduce the video size by the >> * lowres factor, and we don't want that propagated to the stream's >> * codecpar */ >> - av_dict_set(options ? &options[i] : &thread_opt, "lowres", "0", 0); >> + av_dict_set(&options[i], "lowres", "0", 0); >> >> if (ic->codec_whitelist) >> - av_dict_set(options ? &options[i] : &thread_opt, >> "codec_whitelist", ic->codec_whitelist, 0); >> + av_dict_set(&options[i], "codec_whitelist", >> ic->codec_whitelist, 0); >> >> // Try to just open decoders, in case this is enough to get >> parameters. >> // Also ensure that subtitle_header is properly set. >> if (!has_codec_parameters(st, NULL) && sti->request_probe <= 0 || >> st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE) { >> if (codec && !avctx->codec) >> - if (avcodec_open2(avctx, codec, options ? &options[i] : >> &thread_opt) < 0) >> + if (avcodec_open2(avctx, codec, &options[i]) < 0) >> av_log(ic, AV_LOG_WARNING, >> "Failed to open codec in %s\n",__FUNCTION__); >> } >> - if (!options) >> - av_dict_free(&thread_opt); >> } >> >> read_size = 0; >> > > These changes to libavformat are even worse: Even if all the users in > fftools always set options does not mean that all users do; it is not > required. I understand what you mean now.I will look at this part of the code tomorrow. Thank you for your reply in the email. > Mind if I take over and fix this? I really want to fix it myself. I use ffmpeg not long time. But I think this is a good chance for me to learn it. I will try my best to fix this. Thank you very much. > > - Andreas > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
