Logging to investigate a crash

        size_t frameCount;

    };

    virtual ~AudioBufferProvider() {}

protected:

    AudioBufferProvider() : mValid(kValid) { }

    virtual ~AudioBufferProvider() { mValid = kDead; }

public:

    // value representing an invalid presentation timestamp

    static const int64_t kInvalidPTS = 0x7FFFFFFFFFFFFFFFLL;    // <stdint.h> is too painful

    virtual status_t getNextBuffer(Buffer* buffer, int64_t pts = kInvalidPTS) = 0;

    virtual void releaseBuffer(Buffer* buffer) = 0;

    int getValid() const { return mValid; }

    static const int kValid = 'GOOD';

    static const int kDead = 'DEAD';

private:

    int mValid;

};

// ----------------------------------------------------------------------------

        e0 &= ~(1<<i);

        track_t& t = state->tracks[i];

        t.buffer.frameCount = state->frameCount;

        int valid = t.bufferProvider->getValid();

        if (valid != AudioBufferProvider::kValid) {

            ALOGE("invalid bufferProvider=%p name=%d frameCount=%d valid=%#x enabledTracks=%#x",

                    t.bufferProvider, i, t.buffer.frameCount, valid, enabledTracks);

            // expect to crash

        }

        t.bufferProvider->getNextBuffer(&t.buffer, pts);

        t.frameCount = t.buffer.frameCount;

        t.in = t.buffer.raw;