Reduce messages from libjpeg-turbo

src/codec/SkJpegDecoderMgr.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkJpegDecoderMgr.h"
 #include "SkJpegUtility_codec.h"
 
 /*
  * Print information, warning, and error messages
  */
 static void print_message(const j_common_ptr info, const char caller[]) {
     char buffer[JMSG_LENGTH_MAX];
     info->err->format_message(info, buffer);
     SkCodecPrintf("libjpeg error %d <%s> from %s\n", info->err->msg_code, buffer, caller);
 }
 
 /*
- * Reporting functions for libjpeg
+ * Reporting function for error and warning messages.
  */
-static void emit_message(j_common_ptr info, int) {

[msarett, 2015/11/10 15:26:35]

The default implementation of emit_message is much better than this.

It does not print "trace messages" which essentially are info messages and it
only prints the first warning (unless it a very serious warning).

Currently, we just print everything, which is why the output has been so
verbose.

-    print_message(info, "emit_message");
-}
 static void output_message(j_common_ptr info) {

[msarett, 2015/11/10 15:26:35]

By overriding output_message, we can use SkCodecPrintf, which we can turn on or
off.

The default turbo implementation of emit_message calls output_message when it
wants to print a message, so, even though we don't override emit_message, it
also uses SkCodecPrintf.

     print_message(info, "output_message");
 }
 
 bool JpegDecoderMgr::returnFalse(const char caller[]) {
     print_message((j_common_ptr) &fDInfo, caller);
     return false;
 }
 
 SkCodec::Result JpegDecoderMgr::returnFailure(const char caller[], SkCodec::Result result) {
     print_message((j_common_ptr) &fDInfo, caller);
@@ skipping 15 matching lines @@
 {
     // Error manager must be set before any calls to libjeg in order to handle failures
     fDInfo.err = jpeg_std_error(&fErrorMgr);
     fErrorMgr.error_exit = skjpeg_err_exit;
 }
 
 void JpegDecoderMgr::init() {
     jpeg_create_decompress(&fDInfo);
     fInit = true;
     fDInfo.src = &fSrcMgr;
-    fDInfo.err->emit_message = &emit_message;
     fDInfo.err->output_message = &output_message;
 }
 
 JpegDecoderMgr::~JpegDecoderMgr() {
     if (fInit) {
         jpeg_destroy_decompress(&fDInfo);
     }
 }
 
 jmp_buf& JpegDecoderMgr::getJmpBuf() {
     return fErrorMgr.fJmpBuf;
 }
 
 jpeg_decompress_struct* JpegDecoderMgr::dinfo() {
     return &fDInfo;
 }