[FFmpeg-devel] [PATCH v2] lavf/dashenc: Write media trailers when DASH trailer is written.

[Jeyapal, Karthick]

On 11/30/18 11:42 AM, Jeyapal, Karthick wrote:
>
> On 11/29/18 11:58 PM, Andrey Semashev wrote:
>> This commit ensures that all (potentially, long) filesystem activity is
>> performed when the user calls av_write_trailer on the DASH libavformat
>> context, not when freeing the context. Also, this defers media segment
>> deletion until after the media trailers are written.
>> ---
>>  libavformat/dashenc.c | 82 ++++++++++++++++++++++++++++++-------------
>>  1 file changed, 58 insertions(+), 24 deletions(-)
>>
>> diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
>> index 6ce70e0076..ecfd84a32c 100644
>> --- a/libavformat/dashenc.c
>> +++ b/libavformat/dashenc.c
>> @@ -424,8 +424,6 @@ static void dash_free(AVFormatContext *s)
>>          return;
>>      for (i = 0; i < s->nb_streams; i++) {
>>          OutputStream *os = &c->streams[i];
>> -        if (os->ctx && os->ctx_inited)
>> -            av_write_trailer(os->ctx);
>>          if (os->ctx && os->ctx->pb)
>>              ffio_free_dyn_buf(&os->ctx->pb);
>>          ff_format_io_close(s, &os->out);
>> @@ -1331,6 +1329,47 @@ static void dashenc_delete_file(AVFormatContext *s, char *filename) {
>>      }
>>  }
>>  
>> +static int dashenc_delete_segment_file(AVFormatContext *s, const char* file)
>> +{
>> +    DASHContext *c = s->priv_data;
>> +    size_t dirname_len, file_len;
>> +    char filename[1024];
>> +
>> +    dirname_len = strlen(c->dirname);
>> +    if (dirname_len >= sizeof(filename)) {
>> +        av_log(s, AV_LOG_WARNING, "Cannot delete segments as the directory path is too long: %"PRIu64" characters: %s\n",
>> +            (uint64_t)dirname_len, c->dirname);
>> +        return AVERROR(ENAMETOOLONG);
>> +    }
>> +
>> +    memcpy(filename, c->dirname, dirname_len);
>> +
>> +    file_len = strlen(file);
>> +    if ((dirname_len + file_len) >= sizeof(filename)) {
>> +        av_log(s, AV_LOG_WARNING, "Cannot delete segments as the path is too long: %"PRIu64" characters: %s%s\n",
>> +            (uint64_t)(dirname_len + file_len), c->dirname, file);
>> +        return AVERROR(ENAMETOOLONG);
>> +    }
>> +
>> +    memcpy(filename + dirname_len, file, file_len + 1); // include the terminating zero
>> +    dashenc_delete_file(s, filename);
>> +
>> +    return 0;
>> +}
>> +
>> +static inline void dashenc_delete_media_segments(AVFormatContext *s, OutputStream *os, int remove_count)
>> +{
>> +    for (int i = 0; i < remove_count; ++i) {
>> +        dashenc_delete_segment_file(s, os->segments[i]->file);
>> +
>> +        // Delete the segment regardless of whether the file was successfully deleted
>> +        av_free(os->segments[i]);
>> +    }
>> +
>> +    os->nb_segments -= remove_count;
>> +    memmove(os->segments, os->segments + remove_count, os->nb_segments * sizeof(*os->segments));
>> +}
>> +
>>  static int dash_flush(AVFormatContext *s, int final, int stream)
>>  {
>>      DASHContext *c = s->priv_data;
>> @@ -1420,23 +1459,12 @@ static int dash_flush(AVFormatContext *s, int final, int stream)
>>          os->pos += range_length;
>>      }
>>  
>> -    if (c->window_size || (final && c->remove_at_exit)) {
>> +    if (c->window_size) {
>>          for (i = 0; i < s->nb_streams; i++) {
>>              OutputStream *os = &c->streams[i];
>> -            int j;
>> -            int remove = os->nb_segments - c->window_size - c->extra_window_size;
>> -            if (final && c->remove_at_exit)
>> -                remove = os->nb_segments;
>> -            if (remove > 0) {
>> -                for (j = 0; j < remove; j++) {
>> -                    char filename[1024];
>> -                    snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->segments[j]->file);
>> -                    dashenc_delete_file(s, filename);
>> -                    av_free(os->segments[j]);
>> -                }
>> -                os->nb_segments -= remove;
>> -                memmove(os->segments, os->segments + remove, os->nb_segments * sizeof(*os->segments));
>> -            }
>> +            int remove_count = os->nb_segments - c->window_size - c->extra_window_size;
>> +            if (remove_count > 0)
>> +                dashenc_delete_media_segments(s, os, remove_count);
>>          }
>>      }
>>  
>> @@ -1584,6 +1612,7 @@ static int dash_write_packet(AVFormatContext *s, AVPacket *pkt)
>>  static int dash_write_trailer(AVFormatContext *s)
>>  {
>>      DASHContext *c = s->priv_data;
>> +    int i;
>>  
>>      if (s->nb_streams > 0) {
>>          OutputStream *os = &c->streams[0];
>> @@ -1599,14 +1628,19 @@ static int dash_write_trailer(AVFormatContext *s)
>>      }
>>      dash_flush(s, 1, -1);
>>  
>> -    if (c->remove_at_exit) {
>> -        char filename[1024];
>> -        int i;
>> -        for (i = 0; i < s->nb_streams; i++) {
>> -            OutputStream *os = &c->streams[i];
>> -            snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->initfile);
>> -            dashenc_delete_file(s, filename);
>> +    for (i = 0; i < s->nb_streams; ++i) {
>> +        OutputStream *os = &c->streams[i];
>> +        if (os->ctx && os->ctx_inited) {
>> +            av_write_trailer(os->ctx);
>> +        }
>> +
>> +        if (c->remove_at_exit) {
>> +            dashenc_delete_media_segments(s, os, os->nb_segments);
>> +            dashenc_delete_segment_file(s, os->initfile);
>>          }
>> +    }
>> +
>> +    if (c->remove_at_exit) {
>>          dashenc_delete_file(s, s->url);
>>      }
>>  
> LGTM
Hi Andrey,

Could you please rebase this patch with the latest git master. It is throwing some build errors with the latest version.

Regards,
Karthick
>
> Regards,
> Karthick
>
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