Decode residual data that is still in the decoder first.
Also implemented synchronization after seek. git-svn-id: file:///srv/svn/repos/haiku/trunk/current@5730 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
beveloper
parent
fa635d6dce
commit
7f5173b413
@ -14,6 +14,45 @@
|
||||
|
||||
#define DECODE_BUFFER_SIZE (32 * 1024)
|
||||
|
||||
// bit_rate_table[mpeg_version_index][layer_index][bitrate_index]
|
||||
static const int bit_rate_table[4][4][16] =
|
||||
{
|
||||
{ // mpeg version 2.5
|
||||
{ }, // undefined layer
|
||||
{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 }, // layer 3
|
||||
{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 }, // layer 2
|
||||
{ 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0 } // layer 1
|
||||
},
|
||||
{ // undefined version
|
||||
{ },
|
||||
{ },
|
||||
{ },
|
||||
{ }
|
||||
},
|
||||
{ // mpeg version 2
|
||||
{ },
|
||||
{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 },
|
||||
{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 },
|
||||
{ 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0 }
|
||||
},
|
||||
{ // mpeg version 1
|
||||
{ },
|
||||
{ 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0 },
|
||||
{ 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0 },
|
||||
{ 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0}
|
||||
}
|
||||
};
|
||||
|
||||
// frame_rate_table[mpeg_version_index][sampling_rate_index]
|
||||
static const int frame_rate_table[4][4] =
|
||||
{
|
||||
{ 11025, 12000, 8000, 0}, // mpeg version 2.5
|
||||
{ 0, 0, 0, 0 },
|
||||
{ 22050, 24000, 16000, 0}, // mpeg version 2
|
||||
{ 44100, 48000, 32000, 0} // mpeg version 1
|
||||
};
|
||||
|
||||
|
||||
mp3Decoder::mp3Decoder()
|
||||
{
|
||||
InitMP3(&fMpgLibPrivate);
|
||||
@ -26,6 +65,7 @@ mp3Decoder::mp3Decoder()
|
||||
fBitRate = 0;
|
||||
fChannelCount = 0;
|
||||
fOutputBufferSize = 0;
|
||||
fNeedSync = false;
|
||||
}
|
||||
|
||||
|
||||
@ -99,6 +139,7 @@ mp3Decoder::Seek(uint32 seekTo,
|
||||
ExitMP3(&fMpgLibPrivate);
|
||||
InitMP3(&fMpgLibPrivate);
|
||||
fResidualBytes = 0;
|
||||
fNeedSync = true;
|
||||
return B_OK;
|
||||
}
|
||||
|
||||
@ -147,18 +188,43 @@ mp3Decoder::DecodeNextChunk()
|
||||
void *chunkBuffer;
|
||||
int32 chunkSize;
|
||||
media_header mh;
|
||||
int outsize;
|
||||
int result;
|
||||
status_t err;
|
||||
|
||||
// decode residual data that is still in the decoder first
|
||||
result = decodeMP3(&fMpgLibPrivate, 0, 0, (char *)fDecodeBuffer, DECODE_BUFFER_SIZE, &outsize);
|
||||
if (result == MP3_OK) {
|
||||
fResidualBuffer = fDecodeBuffer;
|
||||
fResidualBytes = outsize;
|
||||
return B_OK;
|
||||
}
|
||||
|
||||
// get another chunk and push it to the decoder
|
||||
|
||||
err = GetNextChunk(&chunkBuffer, &chunkSize, &mh);
|
||||
if (err != B_OK)
|
||||
return err;
|
||||
|
||||
// resync after a seek
|
||||
if (fNeedSync) {
|
||||
while (chunkSize > 100) {
|
||||
if (IsValidStream((uint8 *)chunkBuffer, chunkSize))
|
||||
break;
|
||||
chunkBuffer = (uint8 *)chunkBuffer + 1;
|
||||
chunkSize--;
|
||||
}
|
||||
if (chunkSize <= 100) {
|
||||
TRACE("mp3Decoder::Decode: Sync failed\n");
|
||||
return B_ERROR;
|
||||
}
|
||||
fNeedSync = false;
|
||||
}
|
||||
|
||||
fStartTime = mh.start_time;
|
||||
|
||||
//TRACE("mp3Decoder: fStartTime reset to %.6f\n", fStartTime / 1000000.0);
|
||||
|
||||
int outsize;
|
||||
int result;
|
||||
result = decodeMP3(&fMpgLibPrivate, (char *)chunkBuffer, chunkSize, (char *)fDecodeBuffer, DECODE_BUFFER_SIZE, &outsize);
|
||||
if (result == MP3_ERR) {
|
||||
TRACE("mp3Decoder::Decode: decodeMP3 returned MP3_ERR\n");
|
||||
@ -173,6 +239,74 @@ mp3Decoder::DecodeNextChunk()
|
||||
return B_OK;
|
||||
}
|
||||
|
||||
bool
|
||||
mp3Decoder::IsValidStream(uint8 *buffer, int size)
|
||||
{
|
||||
// check 3 consecutive frame headers to make sure
|
||||
// that the length encoded in the header is correct,
|
||||
// and also that mpeg version and layer do not change
|
||||
int length1 = GetFrameLength(buffer);
|
||||
if (length1 < 0 || (length1 + 4) > size)
|
||||
return false;
|
||||
int version_index1 = (buffer[1] >> 3) & 0x03;
|
||||
int layer_index1 = (buffer[1] >> 1) & 0x03;
|
||||
int length2 = GetFrameLength(buffer + length1);
|
||||
if (length2 < 0 || (length1 + length2 + 4) > size)
|
||||
return false;
|
||||
int version_index2 = (buffer[length1 + 1] >> 3) & 0x03;
|
||||
int layer_index2 = (buffer[length1 + 1] >> 1) & 0x03;
|
||||
if (version_index1 != version_index2 || layer_index1 != layer_index1)
|
||||
return false;
|
||||
int length3 = GetFrameLength(buffer + length1 + length2);
|
||||
if (length3 < 0)
|
||||
return false;
|
||||
int version_index3 = (buffer[length1 + length2 + 1] >> 3) & 0x03;
|
||||
int layer_index3 = (buffer[length1 + length2 + 1] >> 1) & 0x03;
|
||||
if (version_index2 != version_index3 || layer_index2 != layer_index3)
|
||||
return false;
|
||||
return true;
|
||||
}
|
||||
|
||||
int
|
||||
mp3Decoder::GetFrameLength(void *header)
|
||||
{
|
||||
uint8 *h = (uint8 *)header;
|
||||
|
||||
if (h[0] != 0xff)
|
||||
return -1;
|
||||
if ((h[1] & 0xe0) != 0xe0)
|
||||
return -1;
|
||||
|
||||
int mpeg_version_index = (h[1] >> 3) & 0x03;
|
||||
int layer_index = (h[1] >> 1) & 0x03;
|
||||
int bitrate_index = (h[2] >> 4) & 0x0f;
|
||||
int sampling_rate_index = (h[2] >> 2) & 0x03;
|
||||
int padding = (h[2] >> 1) & 0x01;
|
||||
/* not interested in the other bits */
|
||||
|
||||
int bitrate = bit_rate_table[mpeg_version_index][layer_index][bitrate_index];
|
||||
int framerate = frame_rate_table[mpeg_version_index][sampling_rate_index];
|
||||
|
||||
if (!bitrate || !framerate)
|
||||
return -1;
|
||||
|
||||
int length;
|
||||
if (layer_index == 3) // layer 1
|
||||
length = ((144 * 1000 * bitrate) / framerate) + (padding * 4);
|
||||
else // layer 2 & 3
|
||||
length = ((144 * 1000 * bitrate) / framerate) + padding;
|
||||
|
||||
#if 0
|
||||
TRACE("%s %s, %s crc, bit rate %d, frame rate %d, padding %d, frame length %d\n",
|
||||
mpeg_version_index == 0 ? "mpeg 2.5" : (mpeg_version_index == 2 ? "mpeg 2" : "mpeg 1"),
|
||||
layer_index == 3 ? "layer 1" : (layer_index == 2 ? "layer 2" : "layer 3"),
|
||||
(h[1] & 0x01) ? "no" : "has",
|
||||
bitrate, framerate, padding, length);
|
||||
#endif
|
||||
|
||||
return length;
|
||||
}
|
||||
|
||||
|
||||
Decoder *
|
||||
mp3DecoderPlugin::NewDecoder()
|
||||
|
||||
@ -21,7 +21,10 @@ public:
|
||||
status_t Decode(void *buffer, int64 *frameCount,
|
||||
media_header *mediaHeader, media_decode_info *info);
|
||||
|
||||
private:
|
||||
status_t DecodeNextChunk();
|
||||
bool IsValidStream(uint8 *buffer, int size);
|
||||
int GetFrameLength(void *header);
|
||||
|
||||
private:
|
||||
struct mpstr fMpgLibPrivate;
|
||||
@ -34,6 +37,7 @@ private:
|
||||
int fBitRate;
|
||||
int fChannelCount;
|
||||
int fOutputBufferSize;
|
||||
bool fNeedSync;
|
||||
};
|
||||
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user