ref: e8a40038cfdeeb7eb764203dda2613faf96f4709
dir: /common/mp4v2/mp4file_io.cpp/
/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is MPEG4IP.
*
* The Initial Developer of the Original Code is Cisco Systems Inc.
* Portions created by Cisco Systems Inc. are
* Copyright (C) Cisco Systems Inc. 2001. All Rights Reserved.
*
* Contributor(s):
* Dave Mackie dmackie@cisco.com
*/
#include "mp4common.h"
// MP4File low level IO support
u_int64_t MP4File::GetPosition(FILE* pFile)
{
if (m_memoryBuffer == NULL) {
if (pFile == NULL) {
ASSERT(m_pFile);
pFile = m_pFile;
}
fpos_t fpos;
if (fgetpos(pFile, &fpos) < 0) {
throw new MP4Error(errno, "MP4GetPosition");
}
uint64_t ret;
FPOS_TO_VAR(fpos, uint64_t, ret);
return ret;
} else {
return m_memoryBufferPosition;
}
}
void MP4File::SetPosition(u_int64_t pos, FILE* pFile)
{
if (m_memoryBuffer == NULL) {
if (pFile == NULL) {
ASSERT(m_pFile);
pFile = m_pFile;
}
fpos_t fpos;
VAR_TO_FPOS(fpos, pos);
if (fsetpos(pFile, &fpos) < 0) {
throw new MP4Error(errno, "MP4SetPosition");
}
} else {
if (pos >= m_memoryBufferSize) {
// abort();
throw new MP4Error("position out of range", "MP4SetPosition");
}
m_memoryBufferPosition = pos;
}
}
u_int64_t MP4File::GetSize()
{
if (m_mode == 'w') {
// we're always positioned at the end of file in write mode
// except for short intervals in ReadSample and FinishWrite routines
// so we rely on the faster approach of GetPosition()
// instead of flushing to disk, and then stat'ing the file
m_fileSize = GetPosition();
} // else read mode, fileSize was determined at Open()
return m_fileSize;
}
u_int32_t MP4File::ReadBytes(u_int8_t* pBytes, u_int32_t numBytes, FILE* pFile)
{
// handle degenerate cases
if (numBytes == 0) {
return 0;
}
ASSERT(pBytes);
WARNING(m_numReadBits > 0);
if (pFile == NULL) {
pFile = m_pFile;
}
ASSERT(pFile);
if (m_memoryBuffer == NULL) {
if (fread(pBytes, 1, numBytes, pFile) != numBytes) {
if (feof(pFile)) {
throw new MP4Error(
"not enough bytes, reached end-of-file",
"MP4ReadBytes");
} else {
throw new MP4Error(errno, "MP4ReadBytes");
}
}
} else {
if (m_memoryBufferPosition + numBytes > m_memoryBufferSize) {
throw new MP4Error(
"not enough bytes, reached end-of-memory",
"MP4ReadBytes");
}
memcpy(pBytes, &m_memoryBuffer[m_memoryBufferPosition], numBytes);
m_memoryBufferPosition += numBytes;
}
return numBytes;
}
u_int32_t MP4File::PeekBytes(u_int8_t* pBytes, u_int32_t numBytes, FILE* pFile)
{
u_int64_t pos = GetPosition(pFile);
ReadBytes(pBytes, numBytes, pFile);
SetPosition(pos, pFile);
return numBytes;
}
void MP4File::EnableMemoryBuffer(u_int8_t* pBytes, u_int64_t numBytes)
{
ASSERT(m_memoryBuffer == NULL);
if (pBytes) {
m_memoryBuffer = pBytes;
m_memoryBufferSize = numBytes;
} else {
if (numBytes) {
m_memoryBufferSize = numBytes;
} else {
m_memoryBufferSize = 4096;
}
m_memoryBuffer = (u_int8_t*)MP4Malloc(m_memoryBufferSize);
}
m_memoryBufferPosition = 0;
}
void MP4File::DisableMemoryBuffer(u_int8_t** ppBytes, u_int64_t* pNumBytes)
{
ASSERT(m_memoryBuffer != NULL);
if (ppBytes) {
*ppBytes = m_memoryBuffer;
}
if (pNumBytes) {
*pNumBytes = m_memoryBufferPosition;
}
m_memoryBuffer = NULL;
m_memoryBufferSize = 0;
m_memoryBufferPosition = 0;
}
void MP4File::WriteBytes(u_int8_t* pBytes, u_int32_t numBytes, FILE* pFile)
{
ASSERT(m_numWriteBits == 0 || m_numWriteBits >= 8);
if (pBytes == NULL || numBytes == 0) {
return;
}
if (m_memoryBuffer == NULL) {
if (pFile == NULL) {
ASSERT(m_pFile);
pFile = m_pFile;
}
u_int32_t rc = fwrite(pBytes, 1, numBytes, pFile);
if (rc != numBytes) {
throw new MP4Error(errno, "MP4WriteBytes");
}
} else {
if (m_memoryBufferPosition + numBytes > m_memoryBufferSize) {
m_memoryBufferSize = 2 * (m_memoryBufferSize + numBytes);
m_memoryBuffer = (u_int8_t*)
MP4Realloc(m_memoryBuffer, m_memoryBufferSize);
}
memcpy(&m_memoryBuffer[m_memoryBufferPosition], pBytes, numBytes);
m_memoryBufferPosition += numBytes;
}
}
u_int64_t MP4File::ReadUInt(u_int8_t size)
{
switch (size) {
case 1:
return ReadUInt8();
case 2:
return ReadUInt16();
case 3:
return ReadUInt24();
case 4:
return ReadUInt32();
case 8:
return ReadUInt64();
default:
ASSERT(false);
return 0;
}
}
void MP4File::WriteUInt(u_int64_t value, u_int8_t size)
{
switch (size) {
case 1:
WriteUInt8(value);
case 2:
WriteUInt16(value);
case 3:
WriteUInt24(value);
case 4:
WriteUInt32(value);
case 8:
WriteUInt64(value);
default:
ASSERT(false);
}
}
u_int8_t MP4File::ReadUInt8()
{
u_int8_t data;
ReadBytes(&data, 1);
return data;
}
void MP4File::WriteUInt8(u_int8_t value)
{
WriteBytes(&value, 1);
}
u_int16_t MP4File::ReadUInt16()
{
u_int8_t data[2];
ReadBytes(&data[0], 2);
return ((data[0] << 8) | data[1]);
}
void MP4File::WriteUInt16(u_int16_t value)
{
u_int8_t data[2];
data[0] = (value >> 8) & 0xFF;
data[1] = value & 0xFF;
WriteBytes(data, 2);
}
u_int32_t MP4File::ReadUInt24()
{
u_int8_t data[3];
ReadBytes(&data[0], 3);
return ((data[0] << 16) | (data[1] << 8) | data[2]);
}
void MP4File::WriteUInt24(u_int32_t value)
{
u_int8_t data[3];
data[0] = (value >> 16) & 0xFF;
data[1] = (value >> 8) & 0xFF;
data[2] = value & 0xFF;
WriteBytes(data, 3);
}
u_int32_t MP4File::ReadUInt32()
{
u_int8_t data[4];
ReadBytes(&data[0], 4);
return ((data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3]);
}
void MP4File::WriteUInt32(u_int32_t value)
{
u_int8_t data[4];
data[0] = (value >> 24) & 0xFF;
data[1] = (value >> 16) & 0xFF;
data[2] = (value >> 8) & 0xFF;
data[3] = value & 0xFF;
WriteBytes(data, 4);
}
u_int64_t MP4File::ReadUInt64()
{
u_int8_t data[8];
u_int64_t result = 0;
u_int64_t temp;
ReadBytes(&data[0], 8);
for (int i = 0; i < 8; i++) {
temp = data[i];
result |= temp << ((7 - i) * 8);
}
return result;
}
void MP4File::WriteUInt64(u_int64_t value)
{
u_int8_t data[8];
for (int i = 7; i >= 0; i--) {
data[i] = value & 0xFF;
value >>= 8;
}
WriteBytes(data, 8);
}
float MP4File::ReadFixed16()
{
u_int8_t iPart = ReadUInt8();
u_int8_t fPart = ReadUInt8();
return iPart + (((float)fPart) / 0x100);
}
void MP4File::WriteFixed16(float value)
{
if (value >= 0x100) {
throw new MP4Error(ERANGE, "MP4WriteFixed16");
}
u_int8_t iPart = (u_int8_t)value;
u_int8_t fPart = (u_int8_t)((value - iPart) * 0x100);
WriteUInt8(iPart);
WriteUInt8(fPart);
}
float MP4File::ReadFixed32()
{
u_int16_t iPart = ReadUInt16();
u_int16_t fPart = ReadUInt16();
return iPart + (((float)fPart) / 0x10000);
}
void MP4File::WriteFixed32(float value)
{
if (value >= 0x10000) {
throw new MP4Error(ERANGE, "MP4WriteFixed32");
}
u_int16_t iPart = (u_int16_t)value;
u_int16_t fPart = (u_int16_t)((value - iPart) * 0x10000);
WriteUInt16(iPart);
WriteUInt16(fPart);
}
float MP4File::ReadFloat()
{
union {
float f;
u_int32_t i;
} u;
u.i = ReadUInt32();
return u.f;
}
void MP4File::WriteFloat(float value)
{
union {
float f;
u_int32_t i;
} u;
u.f = value;
WriteUInt32(u.i);
}
char* MP4File::ReadString()
{
u_int32_t length = 0;
u_int32_t alloced = 64;
char* data = (char*)MP4Malloc(alloced);
do {
if (length == alloced) {
data = (char*)MP4Realloc(data, alloced * 2);
}
ReadBytes((u_int8_t*)&data[length], 1);
length++;
} while (data[length - 1] != 0);
data = (char*)MP4Realloc(data, length);
return data;
}
void MP4File::WriteString(char* string)
{
if (string == NULL) {
static u_int8_t zero = 0;
WriteBytes(&zero, 1);
} else {
WriteBytes((u_int8_t*)string, strlen(string) + 1);
}
}
char* MP4File::ReadCountedString(u_int8_t charSize, bool allowExpandedCount)
{
u_int32_t charLength;
if (allowExpandedCount) {
u_int8_t b;
charLength = 0;
do {
b = ReadUInt8();
charLength += b;
} while (b == 255);
} else {
charLength = ReadUInt8();
}
u_int32_t byteLength = charLength * charSize;
char* data = (char*)MP4Malloc(byteLength + 1);
if (byteLength > 0) {
ReadBytes((u_int8_t*)data, byteLength);
}
data[byteLength] = '\0';
return data;
}
void MP4File::WriteCountedString(char* string,
u_int8_t charSize, bool allowExpandedCount)
{
u_int32_t byteLength;
if (string) {
byteLength = strlen(string);
} else {
byteLength = 0;
}
u_int32_t charLength = byteLength / charSize;
if (allowExpandedCount) {
while (charLength >= 0xFF) {
WriteUInt8(0xFF);
charLength -= 0xFF;
}
WriteUInt8(charLength);
} else {
if (charLength > 255) {
throw new MP4Error(ERANGE, "Length is %d", "MP4WriteCountedString", charLength);
}
WriteUInt8(charLength);
}
if (byteLength > 0) {
WriteBytes((u_int8_t*)string, byteLength);
}
}
u_int64_t MP4File::ReadBits(u_int8_t numBits)
{
ASSERT(numBits > 0);
ASSERT(numBits <= 64);
u_int64_t bits = 0;
for (u_int8_t i = numBits; i > 0; i--) {
if (m_numReadBits == 0) {
ReadBytes(&m_bufReadBits, 1);
m_numReadBits = 8;
}
bits = (bits << 1) | ((m_bufReadBits >> (--m_numReadBits)) & 1);
}
return bits;
}
void MP4File::FlushReadBits()
{
// eat any remaining bits in the read buffer
m_numReadBits = 0;
}
void MP4File::WriteBits(u_int64_t bits, u_int8_t numBits)
{
ASSERT(numBits <= 64);
for (u_int8_t i = numBits; i > 0; i--) {
m_bufWriteBits |=
(((bits >> (i - 1)) & 1) << (8 - ++m_numWriteBits));
if (m_numWriteBits == 8) {
FlushWriteBits();
}
}
}
void MP4File::PadWriteBits(u_int8_t pad)
{
if (m_numWriteBits) {
WriteBits(pad ? 0xFF : 0x00, 8 - m_numWriteBits);
}
}
void MP4File::FlushWriteBits()
{
if (m_numWriteBits > 0) {
WriteBytes(&m_bufWriteBits, 1);
m_numWriteBits = 0;
m_bufWriteBits = 0;
}
}
u_int32_t MP4File::ReadMpegLength()
{
u_int32_t length = 0;
u_int8_t numBytes = 0;
u_int8_t b;
do {
b = ReadUInt8();
length = (length << 7) | (b & 0x7F);
numBytes++;
} while ((b & 0x80) && numBytes < 4);
return length;
}
void MP4File::WriteMpegLength(u_int32_t value, bool compact)
{
if (value > 0x0FFFFFFF) {
throw new MP4Error(ERANGE, "MP4WriteMpegLength");
}
int8_t numBytes;
if (compact) {
if (value <= 0x7F) {
numBytes = 1;
} else if (value <= 0x3FFF) {
numBytes = 2;
} else if (value <= 0x1FFFFF) {
numBytes = 3;
} else {
numBytes = 4;
}
} else {
numBytes = 4;
}
int8_t i = numBytes;
do {
i--;
u_int8_t b = (value >> (i * 7)) & 0x7F;
if (i > 0) {
b |= 0x80;
}
WriteUInt8(b);
} while (i > 0);
}