ref: 2e6f158f4dc9ebc6eb826041254221cba57c4019
parent: 69c3c0e6f0b5ce8ea4efc65a3898c56f4d6bc513
author: Sigrid <ftrvxmtrx@gmail.com>
date: Tue Aug 11 13:25:53 EDT 2020
audio/flacdec: add -s SECONDS option to seek before decoding
--- a/sys/src/cmd/audio/flacdec/flacdec.c
+++ b/sys/src/cmd/audio/flacdec/flacdec.c
@@ -2,6 +2,9 @@
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>
+#define _PLAN9_SOURCE
+#include <utf.h>
+#include <lib9.h>
#include "FLAC/stream_decoder.h"
static int ifd = -1;
@@ -31,6 +34,41 @@
return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
}
+static FLAC__StreamDecoderSeekStatus
+decseek(FLAC__StreamDecoder *dec, FLAC__uint64 absolute_byte_offset, void *client_data)
+{+ if(fseeko(stdin, absolute_byte_offset, SEEK_SET) < 0)
+ return FLAC__STREAM_DECODER_SEEK_STATUS_UNSUPPORTED;
+
+ return FLAC__STREAM_DECODER_SEEK_STATUS_OK;
+}
+
+static FLAC__StreamDecoderTellStatus
+dectell(FLAC__StreamDecoder *dec, FLAC__uint64 *absolute_byte_offset, void *client_data)
+{+ off_t off;
+
+ if((off = ftello(stdin)) < 0)
+ return FLAC__STREAM_DECODER_TELL_STATUS_UNSUPPORTED;
+
+ *absolute_byte_offset = off;
+ return FLAC__STREAM_DECODER_TELL_STATUS_OK;
+}
+
+static FLAC__StreamDecoderTellStatus
+declen(FLAC__StreamDecoder *dec, FLAC__uint64 *stream_length, void *client_data)
+{+ off_t off;
+
+ if((off = ftello(stdin)) < 0 || fseeko(stdin, 0, SEEK_END) < 0)
+ return FLAC__STREAM_DECODER_LENGTH_STATUS_UNSUPPORTED;
+
+ *stream_length = ftello(stdin);
+ fseeko(stdin, off, SEEK_SET);
+
+ return FLAC__STREAM_DECODER_LENGTH_STATUS_OK;
+}
+
static FLAC__StreamDecoderWriteStatus
decoutput(FLAC__StreamDecoder *dec, FLAC__Frame *frame, FLAC__int32 *buffer[], void *client_data)
{@@ -125,13 +163,43 @@
return feof(stdin);
}
+void
+usage(void)
+{+ fprintf(stderr, "usage: %s [-s SECONDS]\n", argv0);
+ exit(1);
+}
+
int main(int argc, char *argv[])
{FLAC__bool ok = true;
FLAC__StreamDecoder *dec = 0;
+ double seek;
+ seek = 0.0;
+ ARGBEGIN{+ case 's':
+ seek = atof(EARGF(usage()));
+ if(seek >= 0.0)
+ break;
+ default:
+ usage();
+ }ARGEND
+
dec = FLAC__stream_decoder_new();
- FLAC__stream_decoder_init_stream(dec, decinput, NULL, NULL, NULL, checkeof, decoutput, NULL, decerror, NULL);
+ FLAC__stream_decoder_init_stream(dec, decinput, decseek, dectell, declen, checkeof, decoutput, NULL, decerror, NULL);
+ if(seek > 0.0){+ FLAC__uint64 srate;
+ do{+ FLAC__stream_decoder_process_single(dec);
+ srate = FLAC__stream_decoder_get_sample_rate(dec);
+ }while(srate == 0);
+ if(!FLAC__stream_decoder_seek_absolute(dec, srate*seek)){+ FLAC__stream_decoder_flush(dec);
+ seek = 0.0;
+ }
+ fprintf(stderr, "time: %g\n", seek);
+ }
FLAC__stream_decoder_process_until_end_of_stream(dec);
FLAC__stream_decoder_finish(dec);
return 0;