Create C++ wrappers for the FFmpeg error functions.

mythtv/libs/libmyth/audio/audioconvert.cpp

@@ -27,6 +27,7 @@
 
 #include "mythconfig.h"
 #include "mythlogging.h"
+#include "mythaverror.h"
 #include "audioconvert.h"
 
 extern "C" {
@@ -596,10 +597,10 @@ class AudioConvertInternal
         int ret = swr_init(m_swr);
         if (ret < 0)
         {
-            char error[AV_ERROR_MAX_STRING_SIZE];
+            std::string error;
             LOG(VB_AUDIO, LOG_ERR, LOC +
                 QString("error initializing resampler context (%1)")
-                .arg(av_make_error_string(error, sizeof(error), ret)));
+                .arg(av_make_error_stdstring(error, ret)));
             swr_free(&m_swr);
             return;
         }

mythtv/libs/libmyth/audio/audiooutput.cpp

@@ -599,7 +599,6 @@ int AudioOutput::DecodeAudio(AVCodecContext *ctx,
                              const AVPacket *pkt)
 {
     bool got_frame = false;
-    char error[AV_ERROR_MAX_STRING_SIZE];
 
     data_size = 0;
     if (!m_frame)
@@ -631,9 +630,10 @@ int AudioOutput::DecodeAudio(AVCodecContext *ctx,
         ret = 0;
     else if (ret < 0)
     {
+        std::string error;
         LOG(VB_AUDIO, LOG_ERR, LOC +
             QString("audio decode error: %1 (%2)")
-            .arg(av_make_error_string(error, sizeof(error), ret))
+            .arg(av_make_error_stdstring(error, ret))
             .arg(got_frame));
         return ret;
     }

mythtv/libs/libmyth/audio/audiooutput.h

@@ -13,6 +13,7 @@
 #include "audiosettings.h"
 #include "audiooutputsettings.h"
 #include "mythcorecontext.h"
+#include "mythaverror.h"
 #include "volumebase.h"
 #include "output.h"
 

mythtv/libs/libmyth/audio/audiooutputdigitalencoder.cpp

@@ -248,10 +248,10 @@ size_t AudioOutputDigitalEncoder::Encode(void *buf, int len, AudioFormat format)
 
         if (ret < 0)
         {
-            char error[AV_ERROR_MAX_STRING_SIZE];
+            std::string error;
             LOG(VB_GENERAL, LOG_ERR, LOC +
                 QString("audio encode error: %1 (%2)")
-                .arg(av_make_error_string(error, sizeof(error), ret))
+                .arg(av_make_error_stdstring(error, ret))
                 .arg(got_packet));
             return ret;
         }

mythtv/libs/libmyth/audio/audiooutpututil.cpp

@@ -246,7 +246,6 @@ int AudioOutputUtil::DecodeAudio(AVCodecContext *ctx,
 {
     MythAVFrame frame;
     bool got_frame = false;
-    char error[AV_ERROR_MAX_STRING_SIZE];
 
     data_size = 0;
     if (!frame)
@@ -271,9 +270,10 @@ int AudioOutputUtil::DecodeAudio(AVCodecContext *ctx,
         ret = 0;
     else if (ret < 0)
     {
+        std::string error;
         LOG(VB_AUDIO, LOG_ERR, LOC +
             QString("audio decode error: %1 (%2)")
-            .arg(av_make_error_string(error, sizeof(error), ret))
+            .arg(av_make_error_stdstring(error, ret))
             .arg(got_frame));
         return ret;
     }

mythtv/libs/libmyth/libmyth.pro

@@ -38,7 +38,7 @@ HEADERS += audio/audiooutputgraph.h
 HEADERS += backendselect.h dbsettings.h
 HEADERS += langsettings.h
 HEADERS +=
-HEADERS += mythcontext.h
+HEADERS += mythaverror.h mythcontext.h
 HEADERS += mythexp.h mythmediamonitor.h
 HEADERS += schemawizard.h
 HEADERS += output.h
@@ -65,7 +65,7 @@ SOURCES += audio/audiooutputgraph.cpp
 SOURCES += backendselect.cpp dbsettings.cpp
 SOURCES += langsettings.cpp
 SOURCES +=
-SOURCES += mythcontext.cpp
+SOURCES += mythaverror.cpp mythcontext.cpp
 SOURCES += mythmediamonitor.cpp
 SOURCES += schemawizard.cpp
 SOURCES += output.cpp
@@ -134,7 +134,7 @@ inc.files += audio/audiooutputsettings.h audio/audiooutpututil.h
 inc.files += audio/audioconvert.h
 inc.files += audio/volumebase.h audio/eldutils.h
 inc.files += inetcomms.h schemawizard.h
-inc.files += mythmediamonitor.h
+inc.files += mythaverror.h mythmediamonitor.h
 inc.files += visual.h output.h langsettings.h
 inc.files += mythexp.h storagegroupeditor.h
 inc.files += mythterminal.h       remoteutil.h

mythtv/libs/libmyth/mythaverror.cpp

@@ -0,0 +1,45 @@
+/*
+ *  Copyright (c) David Hampton 2020
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include <string.h>
+#include "mythaverror.h"
+
+// \brief A quick and dirty C++ equivalent to av_strerror
+//
+// The caller must supply the stdstring.
+//
+// \see av_strerror
+int av_strerror_stdstring (int errnum, std::string &errbuf)
+{
+    errbuf.resize(AV_ERROR_MAX_STRING_SIZE);
+    int rc = av_strerror(errnum, errbuf.data(), errbuf.size());
+    errbuf.resize(strlen(errbuf.data()));
+    return rc;
+}
+
+// \brief A C++ equivalent to av_make_error_string
+//
+// The caller must supply the stdstring so that the data pointer
+// remains valid after this function returns.
+//
+// \see av_make_error_string
+char *av_make_error_stdstring(std::string &errbuf, int errnum)
+{
+    av_strerror_stdstring(errnum, errbuf);
+    return errbuf.data();
+}

mythtv/libs/libmyth/mythaverror.h

@@ -0,0 +1,32 @@
+/*
+ *  Copyright (c) David Hampton 2020
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#ifndef MYTHAVERROR_H
+#define MYTHAVERROR_H
+
+#include <string>
+#include "mythexp.h"
+
+extern "C" {
+#include "libavutil/error.h"
+}
+
+MPUBLIC int av_strerror_stdstring (int errnum, std::string &errbuf);
+MPUBLIC char *av_make_error_stdstring(std::string &errbuf, int errnum);
+
+#endif // MYTHAVERROR_H

mythtv/libs/libmythtv/decoders/avformatdecoder.cpp

@@ -1025,9 +1025,9 @@ int AvFormatDecoder::OpenFile(MythMediaBuffer *Buffer, bool novideo,
             err = avformat_open_input(&m_ic, filename, fmt, nullptr);
             if (err < 0)
             {
-                char error[AV_ERROR_MAX_STRING_SIZE];
-                av_make_error_string(error, sizeof(error), err);
-                LOG(VB_PLAYBACK, LOG_INFO, LOC + QString("Failed to open input ('%1')").arg(error));
+                std::string error;
+                LOG(VB_PLAYBACK, LOG_INFO, LOC + QString("Failed to open input ('%1')")
+                    .arg(av_make_error_stdstring(error, err)));
 
                 // note - m_ic (AVFormatContext) is freed on failure
                 if (retries > 1)
@@ -2519,15 +2519,13 @@ bool AvFormatDecoder::OpenAVCodec(AVCodecContext *avctx, const AVCodec *codec)
     int ret = avcodec_open2(avctx, codec, nullptr);
     if (ret < 0)
     {
-        char error[AV_ERROR_MAX_STRING_SIZE];
-
-        av_make_error_string(error, sizeof(error), ret);
+        std::string error;
         LOG(VB_GENERAL, LOG_ERR, LOC +
             QString("Could not open codec 0x%1, id(%2) type(%3) "
                     "ignoring. reason %4").arg((uint64_t)avctx,0,16)
             .arg(ff_codec_id_string(avctx->codec_id))
             .arg(ff_codec_type_string(avctx->codec_type))
-            .arg(error));
+            .arg(av_make_error_stdstring(error, ret)));
         return false;
     }
 
@@ -3455,20 +3453,20 @@ bool AvFormatDecoder::ProcessVideoPacket(AVStream *curstream, AVPacket *pkt, boo
 
     if (ret < 0 || ret2 < 0)
     {
-        char error[AV_ERROR_MAX_STRING_SIZE];
+        std::string error;
         if (ret < 0)
         {
             LOG(VB_GENERAL, LOG_ERR, LOC +
                 QString("video avcodec_receive_frame error: %1 (%2) gotpicture:%3")
-                .arg(av_make_error_string(error, sizeof(error), ret))
+                .arg(av_make_error_stdstring(error, ret))
                 .arg(ret).arg(gotpicture));
         }
 
         if (ret2 < 0)
         {
             LOG(VB_GENERAL, LOG_ERR, LOC +
                 QString("video avcodec_send_packet error: %1 (%2) gotpicture:%3")
-                .arg(av_make_error_string(error, sizeof(error), ret2))
+                .arg(av_make_error_stdstring(error, ret2))
                 .arg(ret2).arg(gotpicture));
         }
 
@@ -4937,10 +4935,10 @@ bool AvFormatDecoder::GetFrame(DecodeType decodetype, bool &Retry)
 
                 SetEof(true);
                 delete pkt;
-                char errbuf[256];
+                std::string errbuf(256,'\0');
                 QString errmsg;
-                if (av_strerror(retval, errbuf, sizeof errbuf) == 0)
-                    errmsg = QString(errbuf);
+                if (av_strerror_stdstring(retval, errbuf) == 0)
+                    errmsg = QString::fromStdString(errbuf);
                 else
                     errmsg = "UNKNOWN";
 

mythtv/libs/libmythtv/decoders/mythcodeccontext.cpp

@@ -559,11 +559,11 @@ AVBufferRef* MythCodecContext::CreateDevice(AVHWDeviceType Type, MythOpenGLInter
         return result;
     }
 
-    char error[AV_ERROR_MAX_STRING_SIZE];
+    std::string error;
     LOG(VB_PLAYBACK, LOG_ERR, LOC + QString("Failed to create hardware device '%1'%2 Error '%3'")
         .arg(av_hwdevice_get_type_name(Type))
         .arg(Device == nullptr ? "" : QString(" (%1)").arg(Device))
-        .arg(av_make_error_string(error, sizeof(error), res)));
+        .arg(av_make_error_stdstring(error, res)));
     return nullptr;
 }
 

mythtv/libs/libmythtv/decoders/nuppeldecoder.cpp

@@ -898,10 +898,10 @@ bool NuppelDecoder::DecodeFrame(struct rtframeheader *frameheader,
         // received here.
         if (ret < 0)
         {
-            char error[AV_ERROR_MAX_STRING_SIZE];
+            std::string error;
             LOG(VB_GENERAL, LOG_ERR, LOC +
                 QString("video decode error: %1 (%2)")
-                .arg(av_make_error_string(error, sizeof(error), ret))
+                .arg(av_make_error_stdstring(error, ret))
                 .arg(gotpicture));
         }
         if (!gotpicture)

mythtv/libs/libmythtv/io/mythavformatwriter.cpp

@@ -329,9 +329,9 @@ int MythAVFormatWriter::WriteAudioFrame(unsigned char *Buffer, int /*FrameNumber
 
     if (ret < 0)
     {
-        char error[AV_ERROR_MAX_STRING_SIZE];
+        std::string error;
         LOG(VB_GENERAL, LOG_ERR, LOC + QString("audio encode error: %1 (%2)")
-            .arg(av_make_error_string(error, sizeof(error), ret)).arg(got_packet));
+            .arg(av_make_error_stdstring(error, ret)).arg(got_packet));
         return ret;
     }
 

mythtv/libs/libmythtv/mheg/mhi.cpp

@@ -1900,10 +1900,10 @@ void MHIBitmap::CreateFromMPEG(const unsigned char *data, int length)
             len = 0;
         if (len < 0) // Error
         {
-            char error[AV_ERROR_MAX_STRING_SIZE];
+            std::string error;
             LOG(VB_GENERAL, LOG_ERR,
                 QString("[mhi] video decode error: %1 (%2)")
-                .arg(av_make_error_string(error, sizeof(error), len))
+                .arg(av_make_error_stdstring(error, len))
                 .arg(gotPicture));
             goto Close;
         }

mythtv/libs/libmythtv/mythavutil.cpp

@@ -693,9 +693,9 @@ MythStreamInfoList::MythStreamInfoList(QString filename)
                 m_errorMsg = "File could not be opened";
                 break;
             default:
-                char errbuf[256];
-                if (av_strerror(m_errorCode, errbuf, sizeof errbuf) == 0)
-                    m_errorMsg = QString(errbuf);
+                std::string errbuf;
+                if (av_strerror_stdstring(m_errorCode, errbuf) == 0)
+                    m_errorMsg = QString::fromStdString(errbuf);
                 else
                     m_errorMsg = "UNKNOWN";
         }

mythtv/libs/libmythtv/mythframe.h

@@ -9,6 +9,7 @@
 #include <string.h>
 #endif
 #include "mythtvexp.h" // for MTV_PUBLIC
+#include "mythaverror.h"
 
 extern "C" {
 #include "libavcodec/avcodec.h"