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Fix misalined pointer read in the PCM audio provider

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This commit is contained in:
Thomas Goyne 2015-11-21 19:32:43 -08:00
parent 0d72423223
commit 263ccbdc23
1 changed files with 13 additions and 11 deletions
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24
libaegisub/audio/provider_pcm.cpp
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@ -65,14 +65,16 @@ protected:
PCMAudioProvider(fs::path const& filename) : file(filename) { }
template<typename T, typename UInt>
const T *Read(UInt *data_left) {
T Read(UInt *data_left) {
if (*data_left < sizeof(T)) throw file_ended();
if (file.size() - file_pos < sizeof(T)) throw file_ended();
auto data = file.read(file_pos, sizeof(T));
file_pos += sizeof(T);
*data_left -= sizeof(T);
return reinterpret_cast<const T *>(data);
T ret;
memcpy(&ret, data, sizeof(T));
return ret;
}
std::vector<IndexPoint> index_points;
@ -153,17 +155,17 @@ public:
try {
auto data_left = std::numeric_limits<DataSize>::max();
if (*Read<ChunkId>(&data_left) != Impl::riff_id())
if (Read<ChunkId>(&data_left) != Impl::riff_id())
throw AudioDataNotFound("File is not a RIFF file");
data_left = Impl::data_size(*Read<DataSize>(&data_left));
data_left = Impl::data_size(Read<DataSize>(&data_left));
if (*Read<ChunkId>(&data_left) != Impl::wave_id())
if (Read<ChunkId>(&data_left) != Impl::wave_id())
throw AudioDataNotFound("File is not a RIFF WAV file");
while (data_left) {
auto chunk_fcc = *Read<ChunkId>(&data_left);
auto chunk_size = Impl::chunk_size(*Read<DataSize>(&data_left));
auto chunk_fcc = Read<ChunkId>(&data_left);
auto chunk_size = Impl::chunk_size(Read<DataSize>(&data_left));
data_left -= chunk_size;
@ -171,15 +173,15 @@ public:
if (channels || sample_rate || bytes_per_sample)
throw AudioProviderError("Multiple 'fmt ' chunks not supported");
auto compression = *Read<uint16_t>(&chunk_size);
auto compression = Read<uint16_t>(&chunk_size);
if (compression != 1)
throw AudioProviderError("File is not uncompressed PCM");
channels = *Read<uint16_t>(&chunk_size);
sample_rate = *Read<uint32_t>(&chunk_size);
channels = Read<uint16_t>(&chunk_size);
sample_rate = Read<uint32_t>(&chunk_size);
Read<uint32_t>(&chunk_size); // Average bytes per sample; meaningless
Read<uint16_t>(&chunk_size); // Block align
bytes_per_sample = (*Read<uint16_t>(&chunk_size) + 7) / 8;
bytes_per_sample = (Read<uint16_t>(&chunk_size) + 7) / 8;
}
else if (chunk_fcc == Impl::data_id()) {
if (!channels || !sample_rate || !bytes_per_sample)