[FFmpeg-devel] [PATCH 3/3] avformat/avio: remove 4k limit from avio_printf

[Marton Balint]

On Tue, 6 Aug 2019, Nicolas George wrote:

> Marton Balint (12019-08-05):
>> We do this by switching to AVBPrint.
>>
>> Signed-off-by: Marton Balint <cus at passwd.hu>
>> ---
>>  doc/APIchanges        |  3 +++
>>  libavformat/avio.h    |  5 ++++-
>>  libavformat/aviobuf.c | 15 ++++++++++-----
>>  libavformat/version.h |  2 +-
>>  4 files changed, 18 insertions(+), 7 deletions(-)
>>
>> diff --git a/doc/APIchanges b/doc/APIchanges
>> index 0b19fb067d..fe36c34b90 100644
>> --- a/doc/APIchanges
>> +++ b/doc/APIchanges
>> @@ -15,6 +15,9 @@ libavutil:     2017-10-21
>>
>>  API changes, most recent first:
>>
>> +2019-08-xx - xxxxxxxxxx - lavf 58.31.101 - avio.h
>> +  4K limit removed from avio_printf.
>> +
>>  2019-08-xx - xxxxxxxxxx - lavf 58.31.100 - avio.h
>>    Add avio_print_n_strings and avio_print.
>>
>> diff --git a/libavformat/avio.h b/libavformat/avio.h
>> index ca08907917..f2051da18d 100644
>> --- a/libavformat/avio.h
>> +++ b/libavformat/avio.h
>> @@ -571,7 +571,10 @@ int64_t avio_size(AVIOContext *s);
>>   */
>>  int avio_feof(AVIOContext *s);
>>
>> -/** @warning Writes up to 4 KiB per call */
>> +/**
>> + * Writes a formatted string to the context.
>> + * @return number of bytes written, < 0 on error.
>> + */
>>  int avio_printf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3);
>>
>>  /**
>> diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
>> index c37b056b64..007fba6410 100644
>> --- a/libavformat/aviobuf.c
>> +++ b/libavformat/aviobuf.c
>> @@ -1215,14 +1215,19 @@ int avio_closep(AVIOContext **s)
>>  int avio_printf(AVIOContext *s, const char *fmt, ...)
>>  {
>>      va_list ap;
>> -    char buf[4096]; /* update doc entry in avio.h if changed */
>> -    int ret;
>> +    AVBPrint bp;
>>
>
>> +    av_bprint_init(&bp, 0, INT_MAX);
>
> INT_MAX? Should be -1 or AV_BPRINT_SIZE_UNLIMITED.

The function returns an int so it can't signal writing longer strings that 
that.

Regards,
Marton