issue 191: add padding data in AVPacket data

src/AVDemuxer.cpp

@@ -233,7 +233,20 @@ bool AVDemuxer::readFrame()
     pkt->hasKeyFrame = !!(packet.flags & AV_PKT_FLAG_KEY);
     // what about marking packet as invalid and do not use isCorrupt?
     pkt->isCorrupt = !!(packet.flags & AV_PKT_FLAG_CORRUPT);
+#if NO_PADDING_DATA
     pkt->data = QByteArray((const char*)packet.data, packet.size);
+#else
+    /*!
+      larger than the actual read bytes because some optimized bitstream readers read 32 or 64 bits at once and could read over the end.
+      The end of the input buffer avpkt->data should be set to 0 to ensure that no overreading happens for damaged MPEG streams
+     */
+    QByteArray encoded;;
+    encoded.reserve(packet.size + FF_INPUT_BUFFER_PADDING_SIZE);
+    encoded.resize(packet.size);
+    // also copy  padding data(usually 0)
+    memcpy(encoded.data(), packet.data, encoded.capacity());
+    pkt->data = encoded;
+#endif //NO_PADDING_DATA
     pkt->duration = packet.duration;
     //if (packet.dts == AV_NOPTS_VALUE && )
     if (packet.dts != AV_NOPTS_VALUE) //has B-frames

src/AudioDecoder.cpp

@@ -77,9 +77,19 @@ bool AudioDecoder::decode(const QByteArray &encoded)
         return false;
     DPTR_D(AudioDecoder);
     AVPacket packet;
+#if NO_PADDING_DATA
+    /*!
+      larger than the actual read bytes because some optimized bitstream readers read 32 or 64 bits at once and could read over the end.
+      The end of the input buffer avpkt->data should be set to 0 to ensure that no overreading happens for damaged MPEG streams
+     */
+    // auto released by av_buffer_default_free
+    av_new_packet(&packet, encoded.size());
+    memcpy(packet.data, encoded.data(), encoded.size());
+#else
     av_init_packet(&packet);
     packet.size = encoded.size();
     packet.data = (uint8_t*)encoded.constData();
+#endif //NO_PADDING_DATA
 //TODO: use AVPacket directly instead of Packet?
     int ret = avcodec_decode_audio4(d.codec_ctx, d.frame, &d.got_frame_ptr, &packet);
     d.undecoded_size = qMin(encoded.size() - ret, encoded.size());

src/VideoDecoderFFmpeg.cpp

@@ -54,10 +54,19 @@ bool VideoDecoderFFmpeg::decode(const QByteArray &encoded)
         return false;
     DPTR_D(VideoDecoderFFmpeg);
     AVPacket packet;
+#if NO_PADDING_DATA
+    /*!
+      larger than the actual read bytes because some optimized bitstream readers read 32 or 64 bits at once and could read over the end.
+      The end of the input buffer avpkt->data should be set to 0 to ensure that no overreading happens for damaged MPEG streams
+     */
+    // auto released by av_buffer_default_free
+    av_new_packet(&packet, encoded.size());
+    memcpy(packet.data, encoded.data(), encoded.size());
+#else
     av_init_packet(&packet);
     packet.size = encoded.size();
     packet.data = (uint8_t*)encoded.constData();
-
+#endif //NO_PADDING_DATA
 //TODO: use AVPacket directly instead of Packet?
     //AVStream *stream = format_context->streams[stream_idx];