On 05/28/2010 04:38 PM, Olivier Guilyardi wrote:
> Hi,
>
> I am working on an application which records directly into a FLAC file. For
> this
> purpose I'm using the FLAC stream encoder interface.
>
> It works fine, but if my application is killed during encoding, the metadata
> is
> not being updated since the file isn't closed properly by calling
> FLAC__stream_encoder_finish().
>
> Thus when opening the file afterwards for playback, it is possible to decode
> audio data but the FLAC__StreamMetadata.data.stream_info.total_samples field
> is
> equals to zero.
>
> This is a true problem because it looks like data loss to the user, especially
> if he/she's been recording for hours...
>
> So I'm looking for a way to update the metadata periodically during encoding,
> before calling FLAC__stream_encoder_finish().
>
> Is this possible?
For the records, I ended up with adding FLAC__stream_encoder_flush(), as shown
in the attached diff.
It's certainly not perfect, for instance it won't work for the OGG container.
But it apparently works for me.
--
Olivier
--- src/libFLAC/stream_encoder.c (.../vendor/flac/1.2.1) (revision 482)
+++ src/libFLAC/stream_encoder.c (.../trunk/lib/flac) (revision 482)
@@ -1398,6 +1398,28 @@
#endif
}
+FLAC_API FLAC__bool FLAC__stream_encoder_flush(FLAC__StreamEncoder *encoder) {
+ FLAC__bool error = false;
+ FLAC__uint64 offset;
+
+ if(!encoder->private_->tell_callback
+ || encoder->private_->tell_callback(encoder, &offset,
encoder->private_->client_data) == FLAC__STREAM_ENCODER_TELL_STATUS_ERROR) {
+ return false;
+ }
+
+ update_metadata_(encoder);
+
+ /* check if an error occurred while updating metadata */
+ if(encoder->protected_->state != FLAC__STREAM_ENCODER_OK)
+ error = true;
+
+ if(!encoder->private_->seek_callback
+ || encoder->private_->seek_callback(encoder, offset,
encoder->private_->client_data) != FLAC__STREAM_ENCODER_SEEK_STATUS_OK)
+ error = true;
+
+ return !error;
+}
+
FLAC_API FLAC__bool FLAC__stream_encoder_set_verify(FLAC__StreamEncoder
*encoder, FLAC__bool value)
{
FLAC__ASSERT(0 != encoder);
--- include/FLAC/stream_encoder.h (.../vendor/flac/1.2.1) (revision 482)
+++ include/FLAC/stream_encoder.h (.../trunk/lib/flac) (revision 482)
@@ -1700,6 +1700,8 @@
*/
FLAC_API FLAC__bool FLAC__stream_encoder_finish(FLAC__StreamEncoder *encoder);
+FLAC_API FLAC__bool FLAC__stream_encoder_flush(FLAC__StreamEncoder *encoder);
+
/** Submit data for encoding.
* This version allows you to supply the input data via an array of
* pointers, each pointer pointing to an array of \a samples samples
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