dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-19 23:39:58 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

add incremental decoding

Browse Source 
The object WebPIDecoder is available to store the
decoding state. The flow is typically:

   WebPIDecoder* const idec = WebPINew(mode);
   while (has_more_data) {
     // ... (get additional data)
     status = WebPIAppend(idec, new_data, new_data_size);
     if (status != VP8_STATUS_SUSPENDED ||
       break;
     }

     // The above call decodes the current available buffer.
     // Part of the image can now be refreshed by calling to
     // WebPIDecGetRGB()/WebPIDecGetYUV() etc.
   }
   WebPIDelete(idec);

Doing so, one can try and decode new macroblocks everytime fresh
bytes are available.
There's two operating modes: either appending fresh bytes, or
updating the whole buffer with additional data in the end.
The latter requires less memcpy()'s

main patch by Somnath Banerjee (somnath at google.com)

Change-Id: Ie81cbd0b50f175743af06b1f964de838b9a10a4a
This commit is contained in:
Pascal Massimino
2011-03-23 18:03:53 -07:00
parent 1f28832834
commit 8bf76fe0c8
10 changed files with 748 additions and 79 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
src/webp/decode_vp8.h
View File

@ -12,7 +12,7 @@
#ifndef WEBP_WEBP_DECODE_VP8_H_
#define WEBP_WEBP_DECODE_VP8_H_
#include "decode.h"
#include "webp/decode.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
@ -105,18 +105,6 @@ int VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io);
// Returns false in case of error.
int VP8Decode(VP8Decoder* const dec, VP8Io* const io);
// Enumeration of the codes returned by VP8Status()
typedef enum {
VP8_STATUS_OK = 0,
VP8_STATUS_OUT_OF_MEMORY,
VP8_STATUS_INVALID_PARAM,
VP8_STATUS_BITSTREAM_ERROR,
VP8_STATUS_UNSUPPORTED_FEATURE,
VP8_STATUS_SUSPENDED,
VP8_STATUS_USER_ABORT,
VP8_STATUS_NOT_ENOUGH_DATA,
} VP8StatusCode;
// Return current status of the decoder:
VP8StatusCode VP8Status(VP8Decoder* const dec);