[FFmpeg-devel] [PATCH] avfilter/af_atempo: Make ffplay display correct timestamps when seeking

[Pavel Koshevoy]

On 5/8/19 1:13 AM, Paul B Mahol wrote:
> On 5/8/19, Pavel Koshevoy <pkoshevoy at gmail.com> wrote:
>> NOTE: this is a refinement of the patch from Paul B Mahol
>> offset all output timestamps by same amount of first input timestamp
>> ---
>>   libavfilter/af_atempo.c | 11 ++++++++++-
>>   1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c
>> index bfdad7d76b..688dac5464 100644
>> --- a/libavfilter/af_atempo.c
>> +++ b/libavfilter/af_atempo.c
>> @@ -103,6 +103,9 @@ typedef struct ATempoContext {
>>       // 1: output sample position
>>       int64_t position[2];
>>
>> +    // first input timestamp, all other timestamps are offset by this one
>> +    int64_t start_pts;
>> +
>>       // sample format:
>>       enum AVSampleFormat format;
>>
>> @@ -186,6 +189,7 @@ static void yae_clear(ATempoContext *atempo)
>>
>>       atempo->nfrag = 0;
>>       atempo->state = YAE_LOAD_FRAGMENT;
>> +    atempo->start_pts = AV_NOPTS_VALUE;
>>
>>       atempo->position[0] = 0;
>>       atempo->position[1] = 0;
>> @@ -1068,7 +1072,7 @@ static int push_samples(ATempoContext *atempo,
>>       atempo->dst_buffer->nb_samples  = n_out;
>>
>>       // adjust the PTS:
>> -    atempo->dst_buffer->pts =
>> +    atempo->dst_buffer->pts = atempo->start_pts +
>>           av_rescale_q(atempo->nsamples_out,
>>                        (AVRational){ 1, outlink->sample_rate },
>>                        outlink->time_base);
>> @@ -1097,6 +1101,11 @@ static int filter_frame(AVFilterLink *inlink, AVFrame
>> *src_buffer)
>>       const uint8_t *src = src_buffer->data[0];
>>       const uint8_t *src_end = src + n_in * atempo->stride;
>>
>> +    if (atempo->start_pts == AV_NOPTS_VALUE)
>> +        atempo->start_pts = av_rescale_q(src_buffer->pts,
>> +                                         inlink->time_base,
>> +                                         outlink->time_base);
>> +
>>       while (src < src_end) {
>>           if (!atempo->dst_buffer) {
>>               atempo->dst_buffer = ff_get_audio_buffer(outlink, n_out);
>> --
>> 2.16.4
> Should be fine.


Pushed, thank you.
     Pavel.