[FFmpeg-devel] [PATCH 1/2] avformat/microdvd: Use \n instead of \0 to end file header

Andreas Rheinhardt andreas.rheinhardt at gmail.com
Fri Dec 27 05:25:00 EET 2019


Andreas Rheinhardt:
> Andreas Rheinhardt:
>> Up until now, the microdvd demuxer uses av_strdup() to allocate the
>> extradata from a string; its length is set to strlen() + 1, i.e.
>> including the \0 at the end. Upon remuxing, the muxer would simply copy
>> the extradata at the beginning, including the \0.
>>
>> This commit changes this by not adding the \0 to the size of the
>> extradata; the muxer now delimits extradata by inserting a \n. This
>> required to change the subtitles-microdvd-remux FATE-test.
>>
>> Furthermore, the extradata is now allocated with zeroed padding.
>>
>> The microdvd decoder is not affected by this, as it didn't use the size
>> of the extradata at all, but treated it as a C-string.
>>
>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
>> ---
>>  libavformat/microdvddec.c         |   9 +++++----
>>  libavformat/microdvdenc.c         |   1 +
>>  tests/ref/fate/sub-microdvd-remux | Bin 416 -> 416 bytes
>>  3 files changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/libavformat/microdvddec.c b/libavformat/microdvddec.c
>> index ca9086afe9..08e6fca09c 100644
>> --- a/libavformat/microdvddec.c
>> +++ b/libavformat/microdvddec.c
>> @@ -117,10 +117,11 @@ static int microdvd_read_header(AVFormatContext *s)
>>                  continue;
>>              }
>>              if (!st->codecpar->extradata && sscanf(line, "{DEFAULT}{}%c", &c) == 1) {
>> -                st->codecpar->extradata = av_strdup(line + 11);
>> -                if (!st->codecpar->extradata)
>> -                    return AVERROR(ENOMEM);
>> -                st->codecpar->extradata_size = strlen(st->codecpar->extradata) + 1;
>> +                int ret, size = strlen(line + 11);
>> +                ret = ff_alloc_extradata(st->codecpar, size);
>> +                if (ret < 0)
>> +                    return ret;
>> +                memcpy(st->codecpar->extradata, line + 11, size);
>>                  continue;
>>              }
>>          }
>> diff --git a/libavformat/microdvdenc.c b/libavformat/microdvdenc.c
>> index 04f475b645..6639651e02 100644
>> --- a/libavformat/microdvdenc.c
>> +++ b/libavformat/microdvdenc.c
>> @@ -36,6 +36,7 @@ static int microdvd_write_header(struct AVFormatContext *s)
>>      if (par->extradata && par->extradata_size > 0) {
>>          avio_write(s->pb, "{DEFAULT}{}", 11);
>>          avio_write(s->pb, par->extradata, par->extradata_size);
>> +        avio_w8(s->pb, '\n');
>>          avio_flush(s->pb);
>>      }
>>  
>> diff --git a/tests/ref/fate/sub-microdvd-remux b/tests/ref/fate/sub-microdvd-remux
>> index a71da99031fdc4bff13ea7124c046e761a650dc8..92ff233f56b6fec33d4e9e0698ec43377ea5fab7 100644
>> GIT binary patch
>> delta 12
>> TcmZ3$ynuOvE+f}Qy&^^c7%l^0
>>
>> delta 12
>> TcmZ3$ynuOvE+fN6y&^^c7yJWP
>>
> Ping.
> 
> - Andreas
> 
Ping.

- Andreas


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