初始化

cocos2d-x/cocos/audio/android/mp3reader.cpp

@@ -0,0 +1,540 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#define LOG_TAG "mp3reader"
+
+#include <stdlib.h>
+#include <assert.h>
+#include <stdint.h>
+#include <string.h> // Resolves that memset, memcpy aren't found while APP_PLATFORM >= 22 on Android
+#include <vector>
+#include "audio/android/cutils/log.h"
+
+#include "pvmp3decoder_api.h"
+#include "audio/android/mp3reader.h"
+
+static uint32_t U32_AT(const uint8_t *ptr) {
+    return ptr[0] << 24 | ptr[1] << 16 | ptr[2] << 8 | ptr[3];
+}
+
+static bool parseHeader(
+        uint32_t header, size_t *frame_size,
+        uint32_t *out_sampling_rate = NULL, uint32_t *out_channels = NULL ,
+        uint32_t *out_bitrate = NULL, uint32_t *out_num_samples = NULL) {
+    *frame_size = 0;
+
+    if (out_sampling_rate) {
+        *out_sampling_rate = 0;
+    }
+
+    if (out_channels) {
+        *out_channels = 0;
+    }
+
+    if (out_bitrate) {
+        *out_bitrate = 0;
+    }
+
+    if (out_num_samples) {
+        *out_num_samples = 1152;
+    }
+
+    if ((header & 0xffe00000) != 0xffe00000) {
+        return false;
+    }
+
+    unsigned version = (header >> 19) & 3;
+
+    if (version == 0x01) {
+        return false;
+    }
+
+    unsigned layer = (header >> 17) & 3;
+
+    if (layer == 0x00) {
+        return false;
+    }
+
+    unsigned bitrate_index = (header >> 12) & 0x0f;
+
+    if (bitrate_index == 0 || bitrate_index == 0x0f) {
+        // Disallow "free" bitrate.
+        return false;
+    }
+
+    unsigned sampling_rate_index = (header >> 10) & 3;
+
+    if (sampling_rate_index == 3) {
+        return false;
+    }
+
+    static const int kSamplingRateV1[] = { 44100, 48000, 32000 };
+    int sampling_rate = kSamplingRateV1[sampling_rate_index];
+    if (version == 2 /* V2 */) {
+        sampling_rate /= 2;
+    } else if (version == 0 /* V2.5 */) {
+        sampling_rate /= 4;
+    }
+
+    unsigned padding = (header >> 9) & 1;
+
+    if (layer == 3) {
+        // layer I
+
+        static const int kBitrateV1[] = {
+            32, 64, 96, 128, 160, 192, 224, 256,
+            288, 320, 352, 384, 416, 448
+        };
+
+        static const int kBitrateV2[] = {
+            32, 48, 56, 64, 80, 96, 112, 128,
+            144, 160, 176, 192, 224, 256
+        };
+
+        int bitrate =
+            (version == 3 /* V1 */)
+                ? kBitrateV1[bitrate_index - 1]
+                : kBitrateV2[bitrate_index - 1];
+
+        if (out_bitrate) {
+            *out_bitrate = bitrate;
+        }
+
+        *frame_size = (12000 * bitrate / sampling_rate + padding) * 4;
+
+        if (out_num_samples) {
+            *out_num_samples = 384;
+        }
+    } else {
+        // layer II or III
+
+        static const int kBitrateV1L2[] = {
+            32, 48, 56, 64, 80, 96, 112, 128,
+            160, 192, 224, 256, 320, 384
+        };
+
+        static const int kBitrateV1L3[] = {
+            32, 40, 48, 56, 64, 80, 96, 112,
+            128, 160, 192, 224, 256, 320
+        };
+
+        static const int kBitrateV2[] = {
+            8, 16, 24, 32, 40, 48, 56, 64,
+            80, 96, 112, 128, 144, 160
+        };
+
+        int bitrate;
+        if (version == 3 /* V1 */) {
+            bitrate = (layer == 2 /* L2 */)
+                ? kBitrateV1L2[bitrate_index - 1]
+                : kBitrateV1L3[bitrate_index - 1];
+
+            if (out_num_samples) {
+                *out_num_samples = 1152;
+            }
+        } else {
+            // V2 (or 2.5)
+
+            bitrate = kBitrateV2[bitrate_index - 1];
+            if (out_num_samples) {
+                *out_num_samples = (layer == 1 /* L3 */) ? 576 : 1152;
+            }
+        }
+
+        if (out_bitrate) {
+            *out_bitrate = bitrate;
+        }
+
+        if (version == 3 /* V1 */) {
+            *frame_size = 144000 * bitrate / sampling_rate + padding;
+        } else {
+            // V2 or V2.5
+            size_t tmp = (layer == 1 /* L3 */) ? 72000 : 144000;
+            *frame_size = tmp * bitrate / sampling_rate + padding;
+        }
+    }
+
+    if (out_sampling_rate) {
+        *out_sampling_rate = sampling_rate;
+    }
+
+    if (out_channels) {
+        int channel_mode = (header >> 6) & 3;
+
+        *out_channels = (channel_mode == 3) ? 1 : 2;
+    }
+
+    return true;
+}
+
+// Mask to extract the version, layer, sampling rate parts of the MP3 header,
+// which should be same for all MP3 frames.
+static const uint32_t kMask = 0xfffe0c00;
+
+static ssize_t sourceReadAt(mp3_callbacks *callback, void* source, off64_t offset, void *data, size_t size) {
+    int retVal = callback->seek(source, offset, SEEK_SET);
+    if (retVal != EXIT_SUCCESS) {
+        return 0;
+    } else {
+       return callback->read(data, 1, size, source);
+    }
+}
+
+// Resync to next valid MP3 frame in the file.
+static bool resync(
+        mp3_callbacks *callback, void* source, uint32_t match_header,
+        off64_t *inout_pos, uint32_t *out_header) {
+
+    if (*inout_pos == 0) {
+        // Skip an optional ID3 header if syncing at the very beginning
+        // of the datasource.
+
+        for (;;) {
+            uint8_t id3header[10];
+            int retVal = sourceReadAt(callback, source, *inout_pos, id3header,
+                                      sizeof(id3header));
+            if (retVal < (ssize_t)sizeof(id3header)) {
+                // If we can't even read these 10 bytes, we might as well bail
+                // out, even if there _were_ 10 bytes of valid mp3 audio data...
+                return false;
+            }
+
+            if (memcmp("ID3", id3header, 3)) {
+                break;
+            }
+
+            // Skip the ID3v2 header.
+
+            size_t len =
+                ((id3header[6] & 0x7f) << 21)
+                | ((id3header[7] & 0x7f) << 14)
+                | ((id3header[8] & 0x7f) << 7)
+                | (id3header[9] & 0x7f);
+
+            len += 10;
+
+            *inout_pos += len;
+
+            ALOGV("skipped ID3 tag, new starting offset is %lld (0x%016llx)",
+                    (long long)*inout_pos, (long long)*inout_pos);
+        }
+
+    }
+
+    off64_t pos = *inout_pos;
+    bool valid = false;
+
+    const int32_t kMaxReadBytes = 1024;
+    const int32_t kMaxBytesChecked = 128 * 1024;
+    uint8_t buf[kMaxReadBytes];
+    ssize_t bytesToRead = kMaxReadBytes;
+    ssize_t totalBytesRead = 0;
+    ssize_t remainingBytes = 0;
+    bool reachEOS = false;
+    uint8_t *tmp = buf;
+
+    do {
+        if (pos >= (off64_t)(*inout_pos + kMaxBytesChecked)) {
+            // Don't scan forever.
+            ALOGV("giving up at offset %lld", (long long)pos);
+            break;
+        }
+
+        if (remainingBytes < 4) {
+            if (reachEOS) {
+                break;
+            } else {
+                memcpy(buf, tmp, remainingBytes);
+                bytesToRead = kMaxReadBytes - remainingBytes;
+
+                /*
+                 * The next read position should start from the end of
+                 * the last buffer, and thus should include the remaining
+                 * bytes in the buffer.
+                 */
+                totalBytesRead = sourceReadAt(callback, source, pos + remainingBytes,
+                                             buf + remainingBytes, bytesToRead);
+
+                if (totalBytesRead <= 0) {
+                    break;
+                }
+                reachEOS = (totalBytesRead != bytesToRead);
+                remainingBytes += totalBytesRead;
+                tmp = buf;
+                continue;
+            }
+        }
+
+        uint32_t header = U32_AT(tmp);
+
+        if (match_header != 0 && (header & kMask) != (match_header & kMask)) {
+            ++pos;
+            ++tmp;
+            --remainingBytes;
+            continue;
+        }
+
+        size_t frame_size;
+        uint32_t sample_rate, num_channels, bitrate;
+        if (!parseHeader(
+                    header, &frame_size,
+                    &sample_rate, &num_channels, &bitrate)) {
+            ++pos;
+            ++tmp;
+            --remainingBytes;
+            continue;
+        }
+
+        // ALOGV("found possible 1st frame at %lld (header = 0x%08x)", (long long)pos, header);
+        // We found what looks like a valid frame,
+        // now find its successors.
+
+        off64_t test_pos = pos + frame_size;
+
+        valid = true;
+        const int FRAME_MATCH_REQUIRED = 3;
+        for (int j = 0; j < FRAME_MATCH_REQUIRED; ++j) {
+            uint8_t tmp[4];
+            ssize_t retval = sourceReadAt(callback, source, test_pos, tmp, sizeof(tmp));
+            if (retval < (ssize_t)sizeof(tmp)) {
+                valid = false;
+                break;
+            }
+
+            uint32_t test_header = U32_AT(tmp);
+
+            ALOGV("subsequent header is %08x", test_header);
+
+            if ((test_header & kMask) != (header & kMask)) {
+                valid = false;
+                break;
+            }
+
+            size_t test_frame_size;
+            if (!parseHeader(test_header, &test_frame_size)) {
+                valid = false;
+                break;
+            }
+
+            ALOGV("found subsequent frame #%d at %lld", j + 2, (long long)test_pos);
+            test_pos += test_frame_size;
+        }
+
+        if (valid) {
+            *inout_pos = pos;
+
+            if (out_header != NULL) {
+                *out_header = header;
+            }
+        } else {
+            ALOGV("no dice, no valid sequence of frames found.");
+        }
+
+        ++pos;
+        ++tmp;
+        --remainingBytes;
+    } while (!valid);
+
+    return valid;
+}
+
+Mp3Reader::Mp3Reader() : mSource(NULL), mCallback(NULL) {
+}
+
+// Initialize the MP3 reader.
+bool Mp3Reader::init(mp3_callbacks *callback, void* source) {
+
+    mSource = source;
+    mCallback = callback;
+    // Open the file.
+    // mFp = fopen(file, "rb");
+    // if (mFp == NULL) return false;
+
+    // Sync to the first valid frame.
+    off64_t pos = 0;
+    uint32_t header;
+    bool success = resync(callback, source, 0 /*match_header*/, &pos, &header);
+    if (!success)
+    {
+        ALOGE("%s, resync failed", __FUNCTION__);
+        return false;
+    }
+
+    mCurrentPos  = pos;
+    mFixedHeader = header;
+
+    size_t frame_size;
+    return parseHeader(header, &frame_size, &mSampleRate,
+                       &mNumChannels, &mBitrate);
+}
+
+// Get the next valid MP3 frame.
+bool Mp3Reader::getFrame(void *buffer, uint32_t *size) {
+
+    size_t frame_size;
+    uint32_t bitrate;
+    uint32_t num_samples;
+    uint32_t sample_rate;
+    for (;;) {
+        ssize_t n = sourceReadAt(mCallback, mSource, mCurrentPos, buffer, 4);
+        if (n < 4) {
+            return false;
+        }
+
+        uint32_t header = U32_AT((const uint8_t *)buffer);
+
+        if ((header & kMask) == (mFixedHeader & kMask)
+            && parseHeader(
+                header, &frame_size, &sample_rate, NULL /*out_channels*/,
+                &bitrate, &num_samples)) {
+            break;
+        }
+
+        // Lost sync.
+        off64_t pos = mCurrentPos;
+        if (!resync(mCallback, mSource, mFixedHeader, &pos, NULL /*out_header*/)) {
+            // Unable to resync. Signalling end of stream.
+            return false;
+        }
+
+        mCurrentPos = pos;
+
+        // Try again with the new position.
+    }
+    ssize_t n = sourceReadAt(mCallback, mSource, mCurrentPos, buffer, frame_size);
+    if (n < (ssize_t)frame_size) {
+        return false;
+    }
+
+    *size = frame_size;
+    mCurrentPos += frame_size;
+    return true;
+}
+
+// Close the MP3 reader.
+void Mp3Reader::close() {
+    assert(mCallback != NULL);
+    mCallback->close(mSource);
+}
+
+Mp3Reader::~Mp3Reader() {
+}
+
+enum {
+    kInputBufferSize = 10 * 1024,
+    kOutputBufferSize = 4608 * 2,
+};
+
+int decodeMP3(mp3_callbacks* cb, void* source, std::vector<char>& pcmBuffer, int* numChannels, int* sampleRate, int* numFrames)
+{
+    // Initialize the config.
+    tPVMP3DecoderExternal config;
+    config.equalizerType = flat;
+    config.crcEnabled = false;
+
+    // Allocate the decoder memory.
+    uint32_t memRequirements = pvmp3_decoderMemRequirements();
+    void *decoderBuf = malloc(memRequirements);
+    assert(decoderBuf != NULL);
+
+    // Initialize the decoder.
+    pvmp3_InitDecoder(&config, decoderBuf);
+
+    // Open the input file.
+    Mp3Reader mp3Reader;
+    bool success = mp3Reader.init(cb, source);
+    if (!success) {
+        ALOGE("mp3Reader.init: Encountered error reading\n");
+        free(decoderBuf);
+        return EXIT_FAILURE;
+    }
+
+    // Open the output file.
+    // SF_INFO sfInfo;
+    // memset(&sfInfo, 0, sizeof(SF_INFO));
+    // sfInfo.channels = mp3Reader.getNumChannels();
+    // sfInfo.format = SF_FORMAT_WAV | SF_FORMAT_PCM_16;
+    // sfInfo.samplerate = mp3Reader.getSampleRate();
+    // SNDFILE *handle = sf_open(argv[2], SFM_WRITE, &sfInfo);
+    // if (handle == NULL) {
+    //     ALOGE("Encountered error writing %s\n", argv[2]);
+    //     mp3Reader.close();
+    //     free(decoderBuf);
+    //     return EXIT_FAILURE;
+    // }
+
+    // Allocate input buffer.
+    uint8_t *inputBuf = static_cast<uint8_t*>(malloc(kInputBufferSize));
+    assert(inputBuf != NULL);
+
+    // Allocate output buffer.
+    int16_t *outputBuf = static_cast<int16_t*>(malloc(kOutputBufferSize));
+    assert(outputBuf != NULL);
+
+    // Decode loop.
+    int retVal = EXIT_SUCCESS;
+    while (1) {
+        // Read input from the file.
+        uint32_t bytesRead;
+        bool success = mp3Reader.getFrame(inputBuf, &bytesRead);
+        if (!success) break;
+
+        *numChannels = mp3Reader.getNumChannels();
+        *sampleRate = mp3Reader.getSampleRate();
+
+        // Set the input config.
+        config.inputBufferCurrentLength = bytesRead;
+        config.inputBufferMaxLength = 0;
+        config.inputBufferUsedLength = 0;
+        config.pInputBuffer = inputBuf;
+        config.pOutputBuffer = outputBuf;
+        config.outputFrameSize = kOutputBufferSize / sizeof(int16_t);
+
+        ERROR_CODE decoderErr;
+        decoderErr = pvmp3_framedecoder(&config, decoderBuf);
+        if (decoderErr != NO_DECODING_ERROR) {
+            ALOGE("Decoder encountered error=%d", decoderErr);
+            retVal = EXIT_FAILURE;
+            break;
+        }
+
+        pcmBuffer.insert(pcmBuffer.end(), (char*)outputBuf, ((char*)outputBuf) + config.outputFrameSize * 2);
+        *numFrames += config.outputFrameSize / mp3Reader.getNumChannels();
+    }
+
+    // Close input reader and output writer.
+    mp3Reader.close();
+    // sf_close(handle);
+
+    // Free allocated memory.
+    free(inputBuf);
+    free(outputBuf);
+    free(decoderBuf);
+
+    return retVal;
+}