On 06/04/14 22:10, Janne Grunau wrote:
> On 2014-04-05 03:41:14 +0200, Luca Barbato wrote:
>> Two less read and somehow match the style of other functions with similar
>> purpose in the codebase.
>
> only in the unlikely case of damaged streams, one read more for
> the expected case.
>
>> ---
>> libavcodec/h264.c | 21 +++++++++++++--------
>> 1 file changed, 13 insertions(+), 8 deletions(-)
>>
>> diff --git a/libavcodec/h264.c b/libavcodec/h264.c
>> index 1a04cc1..daaa5f8 100644
>> --- a/libavcodec/h264.c
>> +++ b/libavcodec/h264.c
>> @@ -1284,18 +1284,23 @@ int ff_set_ref_count(H264Context *h)
>> static int get_nal_start(const uint8_t *buf, int buf_size,
>> int buf_index, int next_avc)
>> {
>> - // start code prefix search
>> - for (; buf_index + 3 < next_avc; buf_index++)
>> - // This should always succeed in the first iteration.
>> - if (buf[buf_index] == 0 &&
>> - buf[buf_index + 1] == 0 &&
>> - buf[buf_index + 2] == 1)
>> - break;
>> + unsigned int var, i;
>>
>> if (buf_index + 3 >= buf_size)
>> return buf_size;
>>
>> - return buf_index + 3;
>> + var = AV_RB24(buf + buf_index);
>> +
>> + for (i = buf_index + 3; i < next_avc; i++) {
>> + var = (var << 8) | buf[i];
>> + if ((var & 0xffffff00) == 0x00000100)
>> + break;
>> + }
>
> i = buf_index + 3
> while (var != 0x000001)
> var = ((var << 8) | buf[i++]) & 0xffffff;
>
>> +
>> + if (i >= buf_size)
>> + return buf_size;
>> +
>> + return i;
>> }
>
> but it can imho stay as it is
The patch can be dropped if you don't like it.
lu
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