Ogg/opus encode/decode updates and two major bug fixes

[mihui]

1. Simplified ogg/opus code
2. Added continuous and interim result configurations
3. Merged OggHelper and OpusHelper because they share code
4. Fixed issue of recording never stops when the continuous option is on
5. Adjusted (fixed) error handling code due to inconsistent error response from service, see https://developer.ibm.com/answers/questions/284164/500-forwarding-error-and-inconsistant-error-json-s/
6. Removed unused header search paths
7. Added microphone permission check, it is related to the issue [STT] No error when mic access was denied #34
8. Expose token in case there is a need to set token outside of Xcode project (Sorry, previous comment is not good, I noticed that there is a requestToken method, but it is not in Android, so I will add it there)
9. Added a flag for refreshing cached token to provide developer an option to prevent 401 error in advance

[nacho4d]

@mihui AFAIK OpusHelper.h is a public header. importing CodecHeader.h in a public header will required clients to import all headers inside and most of them are not public. Could this header to the .m file please? To do so all ogg type mentions will be need to be done in the .m file as class extension.

The less headers we expose the easier/better integration of this library will be I think

[mihui]

I will get back to you. I have tried a little bit, but it seems making headers private or public does not change a thing. I will try something else tomorrow.

[nacho4d]

I was thinking the new OggHelper.h could look as:

@interface OggHelper : NSObject
- (NSData *) getOggOpusHeader:(int) sampleRate opusHeader:(OpusHeader) header;
- (NSMutableData *) writePacket: (NSData*) data frameSize:(int) frameSize rate: (int) sampleRate;
@end

and put all ogg stuff in the OggHelper.m file

#import "OggHelper"
#import "ogg.h"

#import "opus_defines.h"
#import "opus_header.h"
#import "opus_types.h"

static void comment_init(char **comments, long* length, const char *vendor_string);
static void comment_pad(char **comments, long* length, int amount);
#define readint(buf, base) (((buf[base+3]<<24)&0xff000000)| \
((buf[base+2]<<16)&0xff0000)| \
((buf[base+1]<<8)&0xff00)| \
(buf[base]&0xff))
#define writeint(buf, base, val) do{ buf[base+3]=((val)>>24)&0xff; \
buf[base+2]=((val)>>16)&0xff; \
buf[base+1]=((val)>>8)&0xff; \
buf[base]=(val)&0xff; \
}while(0)

@interface OggHelper() {
    ogg_page oggPage;
    ogg_int64_t packetCount;
    ogg_int16_t granulePos;
    ogg_stream_state streamState;
}
@end

@implementation OggHelper
...
@end

However I just realized that now there is OpusHeader in the .h file so maybe is not going to be easy to hide ogg.h and friends. Maybe not possible now...

[nacho4d]

Maybe forward-declarating OpusHeader helps. http://stackoverflow.com/questions/7259238/how-to-forward-typedefd-struct-in-h

[mihui]

OggHelper reference has been deleted in my repo, I migrated those helpers into one OpusHelper because they are all related to Opus, maybe I should delete the file: d2a9b26

[nacho4d]

BTW, Right now is not possible to merge this PR. Can you rebase or merge this branch on master and push it again?

[mihui]

Just found out it was not easy to merge, and I did some optimizations according to the header thing, not only the codec header. Now there are only 8 headers in public in my repo. I will do some updates for merging branches later.

[mihui]

Unable to merge, closing.

[nacho4d]

😢