Fixed sample count error & refactored

src/algorithms/signal_source/adapters/ion_gsms_signal_source.cc

@@ -53,7 +53,7 @@ IONGSMSSignalSource::IONGSMSSignalSource(const ConfigurationInterface* configura
     unsigned int in_streams,
     unsigned int out_streams,
     Concurrent_Queue<pmt::pmt_t>* queue)
-    : SignalSourceBase(configuration, role, "ION_Metadata_Standard_Signal_Source"s),
+    : SignalSourceBase(configuration, role, "ION_GSMS_Signal_Source"s),
       metadata_file_(configuration->property(role + ".metadata_filename"s, "../data/example_capture_metadata.sdrx"s)),
       stream_ids_(parse_comma_list(configuration->property(role + ".streams"s, ""s))),
       metadata_(metadata_file_),

src/algorithms/signal_source/libs/CMakeLists.txt

@@ -52,6 +52,8 @@ if(ENABLE_ION)
     set(OPT_SIGNAL_SOURCE_LIB_HEADERS ${OPT_SIGNAL_SOURCE_LIB_HEADERS} ion_gsms_chunk_data.h)
     set(OPT_SIGNAL_SOURCE_LIB_SOURCES ${OPT_SIGNAL_SOURCE_LIB_SOURCES} ion_gsms_metadata_handler.cc)
     set(OPT_SIGNAL_SOURCE_LIB_HEADERS ${OPT_SIGNAL_SOURCE_LIB_HEADERS} ion_gsms_metadata_handler.h)
+    set(OPT_SIGNAL_SOURCE_LIB_HEADERS ${OPT_SIGNAL_SOURCE_LIB_HEADERS} ion_gsms_stream_encodings.h)
+    set(OPT_SIGNAL_SOURCE_LIB_HEADERS ${OPT_SIGNAL_SOURCE_LIB_HEADERS} ion_gsms_chunk_unpacking_ctx.h)
 endif()
 
 

src/algorithms/signal_source/libs/ion_gsms.cc

@@ -32,7 +32,7 @@ IONGSMSFileSource::IONGSMSFileSource(
     const GnssMetadata::Block& block,
     const std::vector<std::string>& stream_ids)
     : gr::sync_block(
-          "ion_metadata_standard_source",
+          "ion_gsms_file_source",
           gr::io_signature::make(0, 0, 0),
           make_output_signature(block, stream_ids)),
       file_metadata_(file),
@@ -107,7 +107,12 @@ gr::io_signature::sptr IONGSMSFileSource::make_output_signature(const GnssMetada
                                 }))
                                 {
                                     ++nstreams;
-                                    const std::size_t sample_bitsize = stream.Packedbits() / stream.RateFactor();
+                                    std::size_t sample_bitsize = stream.Packedbits() / stream.RateFactor();
+                                    if (stream.Packedbits() >= 2 * stream.RateFactor() * stream.Quantization())
+                                        {
+                                            // Samples have 'Complex' format
+                                            sample_bitsize /= 2;
+                                        }
                                     item_sizes.push_back(bits_to_item_size(sample_bitsize));
                                 }
                         }

src/algorithms/signal_source/libs/ion_gsms_chunk_data.cc

@@ -48,7 +48,12 @@ IONGSMSChunkData::IONGSMSChunkData(const GnssMetadata::Chunk& chunk, const std::
                         {
                             streams_.emplace_back(lump, stream, GnssMetadata::encoding_from_string(stream.Encoding()),output_streams + output_stream_offset);
                             ++output_streams;
-                            const std::size_t sample_bitsize = stream.Packedbits() / stream.RateFactor();
+                            std::size_t sample_bitsize = stream.Packedbits() / stream.RateFactor();
+                            if (stream.Packedbits() >= 2 * stream.RateFactor() * stream.Quantization())
+                                {
+                                    // Samples have 'Complex' format
+                                    sample_bitsize /= 2;
+                                }
                             output_stream_item_size_.push_back(bits_to_item_size(sample_bitsize));
                         }
                     else
@@ -95,6 +100,137 @@ std::size_t IONGSMSChunkData::output_stream_item_size(std::size_t stream_index)
 }
 
 
+template <typename WT>
+void IONGSMSChunkData::unpack_words(gr_vector_void_star& outputs, const std::function<void(int output, int nitems)>& produce)
+{
+    WT* data = static_cast<WT*>(buffer_);
+    // TODO - Swap endiannes if needed
+
+    IONGSMSChunkUnpackingCtx<WT> ctx{
+        chunk_.Shift(),
+        data,
+        countwords_,
+    };
+
+    // Head padding
+    if (padding_bitsize_ > 0 && chunk_.Padding() == GnssMetadata::Chunk::Head)
+        {
+            ctx.shift_padding(padding_bitsize_);
+        }
+
+    // Samples
+    for (const auto& [lump, stream, encoding, output_index] : streams_)
+        {
+            if (output_index == -1)
+                {
+                    // skip stream
+                    ctx.shift_padding(stream.Packedbits());
+                }
+            else
+                {
+                    produce(output_index, write_stream_samples(ctx, lump, stream, encoding, outputs[output_index]));
+                }
+        }
+}
+
+template <typename WT>
+std::size_t IONGSMSChunkData::write_stream_samples(
+    IONGSMSChunkUnpackingCtx<WT>& ctx,
+    const GnssMetadata::Lump& lump,
+    const GnssMetadata::IonStream& stream,
+    const GnssMetadata::StreamEncoding stream_encoding,
+    void*& out)
+{
+    std::size_t sample_bitsize = stream.Packedbits() / stream.RateFactor();
+    std::size_t sample_count = stream.RateFactor();
+
+    if (stream.Packedbits() >= 2 * stream.RateFactor() * stream.Quantization())
+        {
+            // Samples have 'Complex' format
+            sample_bitsize /= 2;
+            sample_count *= 2;
+        }
+
+    if (sample_bitsize <= 8)
+        {
+            write_n_samples<WT, int8_t>(ctx, lump.Shift(), sample_bitsize, sample_count, stream_encoding, out);
+        }
+    else if (sample_bitsize <= 16)
+        {
+            write_n_samples<WT, int16_t>(ctx, lump.Shift(), sample_bitsize, sample_count, stream_encoding, out);
+        }
+    else if (sample_bitsize <= 32)
+        {
+            write_n_samples<WT, int32_t>(ctx, lump.Shift(), sample_bitsize, sample_count, stream_encoding, out);
+        }
+    else if (sample_bitsize <= 64)
+        {
+            write_n_samples<WT, int64_t>(ctx, lump.Shift(), sample_bitsize, sample_count, stream_encoding, out);
+        }
+
+    return sample_count;
+}
+
+template <typename WT, typename OT>
+void IONGSMSChunkData::write_n_samples(
+    IONGSMSChunkUnpackingCtx<WT>& ctx,
+    GnssMetadata::Lump::LumpShift lump_shift,
+    uint8_t sample_bitsize,
+    std::size_t sample_count,
+    GnssMetadata::StreamEncoding stream_encoding,
+    void*& out)
+{
+    if (lump_shift == GnssMetadata::Lump::shiftRight)
+        {
+            auto* sample = static_cast<OT*>(out);
+            sample += sample_count;
+            for (std::size_t i = 0; i < sample_count; ++i)
+                {
+                    ctx.shift_sample(sample_bitsize, sample);
+                    dump_sample(*sample);
+                    decode_sample(sample_bitsize, sample, stream_encoding);
+                    --sample;
+                }
+        }
+    else  // if (lump_shift == GnssMetadata::Lump::shiftLeft || lump_shift == GnssMetadata::Lump::shiftUndefined)
+        {
+            auto* sample = static_cast<OT*>(out);
+            for (std::size_t i = 0; i < sample_count; ++i)
+                {
+                    ctx.shift_sample(sample_bitsize, sample);
+                    dump_sample(*sample);
+                    decode_sample(sample_bitsize, sample, stream_encoding);
+                    ++sample;
+                }
+        }
+}
+
+
+
+// Static utilities
+void IONGSMSChunkData::decode_sample(const uint8_t sample_bitsize, auto* sample, const GnssMetadata::StreamEncoding encoding)
+{
+    using SampleType = std::remove_pointer_t<decltype(sample)>;
+    switch (sample_bitsize)
+        {
+        case 2:
+            *sample = GnssMetadata::two_bit_look_up<SampleType>[encoding][*sample];
+            break;
+        case 3:
+            *sample = GnssMetadata::three_bit_look_up<SampleType>[encoding][*sample];
+            break;
+        case 4:
+            *sample = GnssMetadata::four_bit_look_up<SampleType>[encoding][*sample];
+            break;
+        case 5:
+            *sample = GnssMetadata::five_bit_look_up<SampleType>[encoding][*sample];
+            break;
+        default:
+            // TODO - Is this an error that can happen?
+            // for now we'll just do nothing, if the sample is this wide it may need no decoding
+            break;
+        }
+}
 
 void IONGSMSChunkData::dump_sample(auto value)
 {
@@ -102,7 +238,7 @@ void IONGSMSChunkData::dump_sample(auto value)
     if (count > 0)
         {
             --count;
-            std::cout << "SAMPLE: " << std::bitset<32>(value) << std::endl;
+            // std::cout << "SAMPLE: [0x" << std::hex << value << "] " << std::bitset<32>(value) << std::endl;
         }
 }
 

src/algorithms/signal_source/libs/ion_gsms_chunk_data.h

@@ -18,6 +18,8 @@
 #define ION_GSM_CHUNK_DATA_H
 
 #include "GnssMetadata.h"
+#include "ion_gsms_stream_encodings.h"
+#include "ion_gsms_chunk_unpacking_ctx.h"
 #include <gnuradio/block.h>
 
 #if USE_GLOG_AND_GFLAGS
@@ -72,144 +74,6 @@ void with_word_type(const uint8_t word_size, auto&& callback)
         }
 }
 
-namespace GnssMetadata
-{
-    using StreamEncoding = unsigned char;
-
-    namespace StreamEncodings
-    {
-        constexpr unsigned char SIGN = 0;
-        constexpr unsigned char OB = 1;
-        constexpr unsigned char SM = 2;
-        constexpr unsigned char MS = 3;
-        constexpr unsigned char TC = 4;
-        constexpr unsigned char OG = 5;
-        constexpr unsigned char OBA = 6;
-        constexpr unsigned char SMA = 7;
-        constexpr unsigned char MSA = 8;
-        constexpr unsigned char TCA = 9;
-        constexpr unsigned char OGA = 10;
-        constexpr unsigned char FP = 11;
-    }
-
-    inline StreamEncoding encoding_from_string(const std::string& str)
-    {
-        if (str == "SIGN")
-            {
-                return StreamEncodings::SIGN;
-            }
-        if (str == "OB")
-            {
-                return StreamEncodings::OB;
-            }
-        if (str == "SM")
-            {
-                return StreamEncodings::SM;
-            }
-        if (str == "MS")
-            {
-                return StreamEncodings::MS;
-            }
-        if (str == "TC")
-            {
-                return StreamEncodings::TC;
-            }
-        if (str == "OG")
-            {
-                return StreamEncodings::OG;
-            }
-        if (str == "OBA")
-            {
-                return StreamEncodings::OBA;
-            }
-        if (str == "SMA")
-            {
-                return StreamEncodings::SMA;
-            }
-        if (str == "MSA")
-            {
-                return StreamEncodings::MSA;
-            }
-        if (str == "TCA")
-            {
-                return StreamEncodings::TCA;
-            }
-        if (str == "OGA")
-            {
-                return StreamEncodings::OGA;
-            }
-        if (str == "FP")
-            {
-                return StreamEncodings::FP;
-            }
-        return 0;
-    }
-
-    template <typename T>
-    inline T two_bit_look_up[11][4]
-    {
-        [0] = {},
-        [1   /*OB*/] = {-2, -1, 0, 1},
-        [2   /*SM*/] = {0, 1, 0, -1},
-        [3   /*MS*/] = {0, 0, 1, -1},
-        [4   /*TC*/] = {0, 1, -2, -1},
-        [5   /*OG*/] = {-2, -1, 1, 0},
-        [6  /*OBA*/] = {-3, -1, 1, 3},
-        [7  /*SMA*/] = {1, 3, -1, -3},
-        [8  /*MSA*/] = {1, -1, 3, -3},
-        [9  /*TCA*/] = {1, 3, -3, -1},
-        [10 /*OGA*/] = {-3, -1, 3, 1},
-    };
-
-    template <typename T>
-    inline T three_bit_look_up[11][8]
-    {
-        [0] = {},
-        [1   /*OB*/] = {-4, -3, -2, -1, 0, 1, 2, 3},
-        [2   /*SM*/] = {0, 1, 2, 3, 0, -1, -2, -3},
-        [3   /*MS*/] = {0, 0, 1, -1, 0, 0, 1, -1},
-        [4   /*TC*/] = {0, 1, 2, 3, -4, -3, -2, -1},
-        [5   /*OG*/] = {-4, -3, -1, -2, 3, 2, 0, 1},
-        [6  /*OBA*/] = {-7, -5, -3, -1, 1, 3, 5, 7},
-        [7  /*SMA*/] = {1, 3, 5, 7, -1, -3, -5, -7},
-        [8  /*MSA*/] = {1, -1, 3, -3, 5, -5, 7, -7},
-        [9  /*TCA*/] = {1, 3, 5, 7, -7, -5, -3, -1},
-        [10 /*OGA*/] = {-7, -5, -1, -3, 7, 5, 1, 3},
-    };
-
-    template <typename T>
-    inline T four_bit_look_up[11][16]
-    {
-        [0] = {},
-        [1   /*OB*/] = {-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7},
-        [2   /*SM*/] = {0, 1, 2, 3, 4, 5, 6, 7, 0, -1, -2, -3, -4, -5, -6, -7},
-        [3   /*MS*/] = {0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1},
-        [4   /*TC*/] = {0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1},
-        [5   /*OG*/] = {-8, -7, -5, -6, -1, -2, -4, -3, 7, 6, 4, 5, 0, 1, 3, 2},
-        [6  /*OBA*/] = {-15, -13, -11, -9, -7, -5, -3, -1, 1, 3, 5, 7, 9, 11, 13, 15},
-        [7  /*SMA*/] = {1, 3, 5, 7, 9, 11, 13, 15, -1, -3, -5, -7, -9, -11, -13, -15},
-        [8  /*MSA*/] = {1, -1, 3, -3, 5, -5, 7, -7, 9, -9, 11, -11, 13, -13, 15, -15},
-        [9  /*TCA*/] = {1, 3, 5, 7, 9, 11, 13, 15, -15, -13, -11, -9, -7, -5, -3, -1},
-        [10 /*OGA*/] = {-15, -13, -9, -11, -1, -3, -7, -5, 15, 13, 9, 11, 1, 3, 7, 5},
-    };
-
-    template <typename T>
-    inline T five_bit_look_up[11][32]
-    {
-        [0] = {},
-        [1   /*OB*/] = {-16, -15, -14, -13, -12, -11, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
-        [2   /*SM*/] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, -1, -2, -3, -4, -5, -6, -7, -8, -9, -10, -11, -12, -13, -14, -15},
-        [3   /*MS*/] = {0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1},
-        [4   /*TC*/] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, -16, -15, -14, -13, -12, -11, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1},
-        [5   /*OG*/] = {-16, -15, -13, -14, -9, -10, -12, -11, -1, -2, -4, -3, -8, -7, -5, -6, 15, 14, 12, 13, 8, 9, 11, 10, 0, 1, 3, 2, 7, 6, 4, 5},
-        [6  /*OBA*/] = {-31, -29, -27, -25, -23, -21, -19, -17, -15, -13, -11, -9, -7, -5, -3, -1, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31},
-        [7  /*SMA*/] = {1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, -1, -3, -5, -7, -9, -11, -13, -15, -17, -19, -21, -23, -25, -27, -29, -31},
-        [8  /*MSA*/] = {1, -1, 3, -3, 5, -5, 7, -7, 9, -9, 11, -11, 13, -13, 15, -15, 17, -17, 19, -19, 21, -21, 23, -23, 25, -25, 27, -27, 29, -29, 31, -31},
-        [9  /*TCA*/] = {1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, -31, -29, -27, -25, -23, -21, -19, -17, -15, -13, -11, -9, -7, -5, -3, -1},
-        [10 /*OGA*/] = {-31, -29, -25, -27, -17, -19, -23, -21, -1, -3, -7, -5, -15, -13, -9, -11, 31, 29, 25, 27, 17, 19, 23, 21, 1, 3, 7, 5, 15, 13, 9, 11},
-    };
-}
-
 class IONGSMSChunkData
 {
 public:
@@ -232,258 +96,26 @@ public:
 
 private:
     template <typename WT>
-    struct unpacking_context_t
+    void unpack_words(gr_vector_void_star& outputs, const std::function<void(int output, int nitems)>& produce);
-    {
-        WT* iterator_;
-        WT current_word_;
-        uint8_t bitshift_ = 0;
-    };
-
-    template <typename WT>
-    void unpack_words(gr_vector_void_star& outputs, const std::function<void(int output, int nitems)>& produce)
-    {
-        WT* data = static_cast<WT*>(buffer_);
-        // TODO - Swap endiannes if needed
-
-        unpacking_context_t<WT> ctx{};
-        if (chunk_.Shift() == GnssMetadata::Chunk::Left)
-            {
-                ctx.iterator_ = data;
-            }
-        else if (chunk_.Shift() == GnssMetadata::Chunk::Right)
-            {
-                ctx.iterator_ = &data[countwords_];
-            }
-        advance_word(ctx);  // Initializes ctx.current_word_
-
-        // Head padding
-        if (padding_bitsize_ > 0 && chunk_.Padding() == GnssMetadata::Chunk::Head)
-            {
-                shift_padding(ctx, padding_bitsize_);
-            }
-
-        // Samples
-        for (const auto& [lump, stream, encoding, output_index] : streams_)
-            {
-                if (output_index == -1)
-                    {
-                        skip_stream(ctx, lump, stream);
-                    }
-                else
-                    {
-                        produce(output_index, write_stream_samples(ctx, lump, stream, encoding, outputs[output_index]));
-                    }
-            }
-    }
-
-    template <typename WT>
-    void skip_stream(
-        unpacking_context_t<WT>& ctx,
-        const GnssMetadata::Lump& lump,
-        const GnssMetadata::IonStream& stream)
-    {
-        shift_padding(ctx, stream.Packedbits());
-    }
 
     template <typename WT>
     std::size_t write_stream_samples(
-        unpacking_context_t<WT>& ctx,
+        IONGSMSChunkUnpackingCtx<WT>& ctx,
         const GnssMetadata::Lump& lump,
         const GnssMetadata::IonStream& stream,
-        const GnssMetadata::StreamEncoding stream_encoding,
+        GnssMetadata::StreamEncoding stream_encoding,
-        void*& out)
+        void*& out);
-    {
-        std::size_t sample_bitsize = stream.Packedbits() / stream.RateFactor();
-        std::size_t sample_count = stream.RateFactor();
-
-        if (stream.Packedbits() >= 2 * stream.RateFactor() * stream.Quantization())
-            {
-                // Samples have 'Complex' format
-                sample_bitsize /= 2;
-                sample_count *= 2;
-            }
-
-        if (sample_bitsize <= 8)
-            {
-                write_n_samples<WT, int8_t>(ctx, lump.Shift(), sample_bitsize, sample_count, stream_encoding, out);
-            }
-        else if (sample_bitsize <= 16)
-            {
-                write_n_samples<WT, int16_t>(ctx, lump.Shift(), sample_bitsize, sample_count, stream_encoding, out);
-            }
-        else if (sample_bitsize <= 32)
-            {
-                write_n_samples<WT, int32_t>(ctx, lump.Shift(), sample_bitsize, sample_count, stream_encoding, out);
-            }
-        else if (sample_bitsize <= 64)
-            {
-                write_n_samples<WT, int64_t>(ctx, lump.Shift(), sample_bitsize, sample_count, stream_encoding, out);
-            }
-
-        return sample_count;
-    }
 
     template <typename WT, typename OT>
     void write_n_samples(
-        unpacking_context_t<WT>& ctx,
+        IONGSMSChunkUnpackingCtx<WT>& ctx,
         GnssMetadata::Lump::LumpShift lump_shift,
         uint8_t sample_bitsize,
         std::size_t sample_count,
         GnssMetadata::StreamEncoding stream_encoding,
-        void*& out)
+        void*& out);
-    {
-        if (lump_shift == GnssMetadata::Lump::shiftRight)
-            {
-                auto* sample = static_cast<OT*>(out);
-                sample += sample_count;
-                for (std::size_t i = 0; i < sample_count; ++i)
-                    {
-                        shift_sample(ctx, sample_bitsize, sample);
-                        decode_sample(sample_bitsize, sample, stream_encoding);
-                        --sample;
-                    }
-            }
-        else // if (lump_shift == GnssMetadata::Lump::shiftLeft || lump_shift == GnssMetadata::Lump::shiftUndefined)
-            {
-                auto* sample = static_cast<OT*>(out);
-                for (std::size_t i = 0; i < sample_count; ++i)
-                    {
-                        shift_sample(ctx, sample_bitsize, sample);
-                        decode_sample(sample_bitsize, sample, stream_encoding);
-                        ++sample;
-                    }
-            }
-    }
 
-    template <typename WT, typename OT>
+    static void decode_sample(uint8_t sample_bitsize, auto* sample, GnssMetadata::StreamEncoding encoding);
-    void shift_sample(unpacking_context_t<WT>& ctx, uint8_t sample_bitsize, OT* output, uint8_t output_bit_offset = 0)
-    {
-        const uint8_t word_bitsize = sizeword_ * 8;
-
-        if ((sample_bitsize + (ctx.bitshift_ % word_bitsize)) > word_bitsize)
-            {
-                uint8_t bits_shifted = word_bitsize - (ctx.bitshift_ % word_bitsize);
-
-                if (chunk_.Shift() == GnssMetadata::Chunk::Left)
-                    {
-                        WT mask = ~((1 << (word_bitsize - bits_shifted)) - 1);
-                        dump_sample(ctx.current_word_ & mask);
-                        *output |= ((ctx.current_word_ & mask) >> output_bit_offset);
-                        ctx.current_word_ <<= bits_shifted;
-                    }
-                else if (chunk_.Shift() == GnssMetadata::Chunk::Right)
-                    {
-                        WT mask = ((1 << (bits_shifted)) - 1);
-                        dump_sample(ctx.current_word_ & mask);
-                        *output |= (ctx.current_word_ & mask) << output_bit_offset;
-                        // TODO - reverse bit order of sample? maybe?
-                        ctx.current_word_ >>= bits_shifted;
-                    }
-
-                advance_word(ctx);
-                ctx.bitshift_ += bits_shifted;
-                shift_sample(ctx, sample_bitsize - bits_shifted, output, bits_shifted);
-            }
-        else
-            {
-                if (chunk_.Shift() == GnssMetadata::Chunk::Left)
-                    {
-                        WT mask = ~((1 << (word_bitsize - sample_bitsize)) - 1);
-                        OT sample = (ctx.current_word_ & mask) >> (word_bitsize - sample_bitsize);
-                        dump_sample(sample);
-                        *output |= (sample) >> output_bit_offset;
-                        ctx.current_word_ <<= sample_bitsize;
-                    }
-                else if (chunk_.Shift() == GnssMetadata::Chunk::Right)
-                    {
-                        WT mask = ((1 << (sample_bitsize)) - 1);
-                        dump_sample(ctx.current_word_ & mask);
-                        *output |= (ctx.current_word_ & mask) << output_bit_offset;
-                        // TODO - reverse bit order of sample? maybe?
-                        ctx.current_word_ >>= sample_bitsize;
-                    }
-
-                ctx.bitshift_ += sample_bitsize;
-            }
-    }
-
-    template <typename WT>
-    void shift_padding(unpacking_context_t<WT>& ctx, uint8_t n_bits)
-    {
-        if(n_bits == 0) return;
-
-        const uint8_t word_bitsize = sizeword_ * 8;
-
-        if ((n_bits + (ctx.bitshift_ % word_bitsize)) >= word_bitsize)
-            {
-                uint8_t bits_shifted = word_bitsize - (ctx.bitshift_ % word_bitsize);
-
-                if (chunk_.Shift() == GnssMetadata::Chunk::Left)
-                    {
-                        ctx.current_word_ <<= bits_shifted;
-                    }
-                else if (chunk_.Shift() == GnssMetadata::Chunk::Right)
-                    {
-                        ctx.current_word_ >>= bits_shifted;
-                    }
-
-                advance_word(ctx);
-                ctx.bitshift_ += bits_shifted;
-                shift_padding(ctx, n_bits - bits_shifted);
-            }
-        else
-            {
-                if (chunk_.Shift() == GnssMetadata::Chunk::Left)
-                    {
-                        ctx.current_word_ <<= n_bits;
-                    }
-                else if (chunk_.Shift() == GnssMetadata::Chunk::Right)
-                    {
-                        ctx.current_word_ >>= n_bits;
-                    }
-
-                ctx.bitshift_ += n_bits;
-            }
-    }
-
-    template <typename WT>
-    void advance_word(unpacking_context_t<WT>& ctx)
-    {
-        WT word = *ctx.iterator_;
-        if (chunk_.Shift() == GnssMetadata::Chunk::Left)
-            {
-                ++ctx.iterator_;
-            }
-        else if (chunk_.Shift() == GnssMetadata::Chunk::Right)
-            {
-                --ctx.iterator_;
-            }
-
-        ctx.current_word_ = word;
-    }
-
-    template <typename ST>
-    static void decode_sample(const uint8_t sample_bitsize, ST* sample, const GnssMetadata::StreamEncoding encoding)
-    {
-        switch (sample_bitsize)
-            {
-            case 2:
-                *sample =  GnssMetadata::two_bit_look_up<ST>[encoding][*sample];
-                break;
-            case 3:
-                *sample =  GnssMetadata::three_bit_look_up<ST>[encoding][*sample];
-                break;
-            case 4:
-                *sample =  GnssMetadata::four_bit_look_up<ST>[encoding][*sample];
-                break;
-            case 5:
-                *sample =  GnssMetadata::five_bit_look_up<ST>[encoding][*sample];
-                break;
-            default:
-                // TODO - Is this an error that can happen?
-                break;
-            }
-    }
 
     static void dump_sample(auto value);
 

src/algorithms/signal_source/libs/ion_gsms_chunk_unpacking_ctx.h

@@ -0,0 +1,153 @@
+/*!
+ * \file ion_gsms_chunk_unpacking_ctx.h
+ * \brief Holds state and provides utilities for unpacking samples from a chunk
+ * \author Víctor Castillo Agüero, 2024. victorcastilloaguero(at)gmail.com
+ *
+ * This is a template class, and thus, its member functions must be defined in the header file.
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#ifndef ION_GSM_CHUNK_UNPACKING_CTX_H
+#define ION_GSM_CHUNK_UNPACKING_CTX_H
+
+#include "GnssMetadata.h"
+#include <gnuradio/block.h>
+
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
+template <typename WT>
+struct IONGSMSChunkUnpackingCtx
+{
+    static constexpr uint8_t word_bitsize_ = sizeof(WT) * 8;
+
+    const GnssMetadata::Chunk::WordShift word_shift_direction_;
+    WT* iterator_;  // Not owned by this class, must not destroy
+    WT current_word_;
+    uint8_t bitshift_ = 0;
+
+    IONGSMSChunkUnpackingCtx(
+        const GnssMetadata::Chunk::WordShift word_shift,
+        WT* data_buffer,
+        uint8_t data_buffer_word_count) : word_shift_direction_(word_shift)
+    {
+        if (word_shift_direction_ == GnssMetadata::Chunk::Left)
+            {
+                iterator_ = data_buffer;
+            }
+        else if (word_shift_direction_ == GnssMetadata::Chunk::Right)
+            {
+                iterator_ = &data_buffer[data_buffer_word_count];
+            }
+        advance_word();  // Initializes current_word_
+    }
+
+    void advance_word()
+    {
+        WT word = *iterator_;
+        if (word_shift_direction_ == GnssMetadata::Chunk::Left)
+            {
+                ++iterator_;
+            }
+        else if (word_shift_direction_ == GnssMetadata::Chunk::Right)
+            {
+                --iterator_;
+            }
+
+        current_word_ = word;
+    }
+
+    void shift_current_word(uint8_t n)
+    {
+        if (word_shift_direction_ == GnssMetadata::Chunk::Left)
+            {
+                current_word_ <<= n;
+            }
+        else if (word_shift_direction_ == GnssMetadata::Chunk::Right)
+            {
+                current_word_ >>= n;
+            }
+
+        bitshift_ += n;
+        if (bitshift_ >= word_bitsize_)
+            {
+                advance_word();
+                bitshift_ -= word_bitsize_;
+            }
+    }
+
+    void shift_padding(uint8_t n_bits)
+    {
+        if (n_bits == 0)
+            {
+                return;
+            }
+
+        if ((n_bits + (bitshift_ % word_bitsize_)) >= word_bitsize_)
+            {
+                const uint8_t bits_shifted = word_bitsize_ - (bitshift_ % word_bitsize_);
+
+                shift_current_word(bits_shifted);
+                shift_padding(n_bits - bits_shifted);
+            }
+        else
+            {
+                shift_current_word(n_bits);
+            }
+    }
+
+    template <typename OT>
+    void shift_sample(const uint8_t sample_bitsize, OT* output, uint8_t output_bit_offset = 0)
+    {
+        if ((sample_bitsize + (bitshift_ % word_bitsize_)) > word_bitsize_)
+            {
+                const uint8_t bits_shifted = word_bitsize_ - (bitshift_ % word_bitsize_);
+
+                if (word_shift_direction_ == GnssMetadata::Chunk::Left)
+                    {
+                        WT mask = ~((1 << (word_bitsize_ - bits_shifted)) - 1);
+                        *output |= ((current_word_ & mask) >> output_bit_offset);
+                    }
+                else if (word_shift_direction_ == GnssMetadata::Chunk::Right)
+                    {
+                        WT mask = ((1 << (bits_shifted)) - 1);
+                        *output |= (current_word_ & mask) << output_bit_offset;
+                        // TODO - reverse bit order of sample? maybe?
+                    }
+
+                shift_current_word(bits_shifted);
+                shift_sample(sample_bitsize - bits_shifted, output, bits_shifted);
+            }
+        else
+            {
+                if (word_shift_direction_ == GnssMetadata::Chunk::Left)
+                    {
+                        WT mask = ~((1 << (word_bitsize_ - sample_bitsize)) - 1);
+                        OT sample = (current_word_ & mask) >> (word_bitsize_ - sample_bitsize);
+                        *output |= (sample) >> output_bit_offset;
+                    }
+                else if (word_shift_direction_ == GnssMetadata::Chunk::Right)
+                    {
+                        WT mask = ((1 << (sample_bitsize)) - 1);
+                        *output |= (current_word_ & mask) << output_bit_offset;
+                        // TODO - reverse bit order of sample? maybe?
+                    }
+
+                shift_current_word(sample_bitsize);
+            }
+    }
+};
+
+#endif //ION_GSM_CHUNK_UNPACKING_CTX_H

src/algorithms/signal_source/libs/ion_gsms_stream_encodings.h

@@ -0,0 +1,164 @@
+/*!
+ * \file ion_gsms_stream_encodings.h
+ * \brief Implements look up tables for all encodings in the standard
+ * \author Víctor Castillo Agüero, 2024. victorcastilloaguero(at)gmail.com
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#ifndef ION_GSM_STREAM_ENCODINGS_H
+#define ION_GSM_STREAM_ENCODINGS_H
+
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
+namespace GnssMetadata
+{
+    using StreamEncoding = unsigned char;
+
+    namespace StreamEncodings
+    {
+        constexpr unsigned char SIGN = 0;
+        constexpr unsigned char OB = 1;
+        constexpr unsigned char SM = 2;
+        constexpr unsigned char MS = 3;
+        constexpr unsigned char TC = 4;
+        constexpr unsigned char OG = 5;
+        constexpr unsigned char OBA = 6;
+        constexpr unsigned char SMA = 7;
+        constexpr unsigned char MSA = 8;
+        constexpr unsigned char TCA = 9;
+        constexpr unsigned char OGA = 10;
+        constexpr unsigned char FP = 11;
+    }
+
+    inline StreamEncoding encoding_from_string(const std::string& str)
+    {
+        if (str == "SIGN")
+            {
+                return StreamEncodings::SIGN;
+            }
+        if (str == "OB")
+            {
+                return StreamEncodings::OB;
+            }
+        if (str == "SM")
+            {
+                return StreamEncodings::SM;
+            }
+        if (str == "MS")
+            {
+                return StreamEncodings::MS;
+            }
+        if (str == "TC")
+            {
+                return StreamEncodings::TC;
+            }
+        if (str == "OG")
+            {
+                return StreamEncodings::OG;
+            }
+        if (str == "OBA")
+            {
+                return StreamEncodings::OBA;
+            }
+        if (str == "SMA")
+            {
+                return StreamEncodings::SMA;
+            }
+        if (str == "MSA")
+            {
+                return StreamEncodings::MSA;
+            }
+        if (str == "TCA")
+            {
+                return StreamEncodings::TCA;
+            }
+        if (str == "OGA")
+            {
+                return StreamEncodings::OGA;
+            }
+        if (str == "FP")
+            {
+                return StreamEncodings::FP;
+            }
+        return 0;
+    }
+
+    template <typename T>
+    inline T two_bit_look_up[11][4]
+    {
+        [0] = {},
+        [1   /*OB*/] = {-2, -1, 0, 1},
+        [2   /*SM*/] = {0, 1, 0, -1},
+        [3   /*MS*/] = {0, 0, 1, -1},
+        [4   /*TC*/] = {0, 1, -2, -1},
+        [5   /*OG*/] = {-2, -1, 1, 0},
+        [6  /*OBA*/] = {-3, -1, 1, 3},
+        [7  /*SMA*/] = {1, 3, -1, -3},
+        [8  /*MSA*/] = {1, -1, 3, -3},
+        [9  /*TCA*/] = {1, 3, -3, -1},
+        [10 /*OGA*/] = {-3, -1, 3, 1},
+    };
+
+    template <typename T>
+    inline T three_bit_look_up[11][8]
+    {
+        [0] = {},
+        [1   /*OB*/] = {-4, -3, -2, -1, 0, 1, 2, 3},
+        [2   /*SM*/] = {0, 1, 2, 3, 0, -1, -2, -3},
+        [3   /*MS*/] = {0, 0, 1, -1, 0, 0, 1, -1},
+        [4   /*TC*/] = {0, 1, 2, 3, -4, -3, -2, -1},
+        [5   /*OG*/] = {-4, -3, -1, -2, 3, 2, 0, 1},
+        [6  /*OBA*/] = {-7, -5, -3, -1, 1, 3, 5, 7},
+        [7  /*SMA*/] = {1, 3, 5, 7, -1, -3, -5, -7},
+        [8  /*MSA*/] = {1, -1, 3, -3, 5, -5, 7, -7},
+        [9  /*TCA*/] = {1, 3, 5, 7, -7, -5, -3, -1},
+        [10 /*OGA*/] = {-7, -5, -1, -3, 7, 5, 1, 3},
+    };
+
+    template <typename T>
+    inline T four_bit_look_up[11][16]
+    {
+        [0] = {},
+        [1   /*OB*/] = {-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7},
+        [2   /*SM*/] = {0, 1, 2, 3, 4, 5, 6, 7, 0, -1, -2, -3, -4, -5, -6, -7},
+        [3   /*MS*/] = {0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1},
+        [4   /*TC*/] = {0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1},
+        [5   /*OG*/] = {-8, -7, -5, -6, -1, -2, -4, -3, 7, 6, 4, 5, 0, 1, 3, 2},
+        [6  /*OBA*/] = {-15, -13, -11, -9, -7, -5, -3, -1, 1, 3, 5, 7, 9, 11, 13, 15},
+        [7  /*SMA*/] = {1, 3, 5, 7, 9, 11, 13, 15, -1, -3, -5, -7, -9, -11, -13, -15},
+        [8  /*MSA*/] = {1, -1, 3, -3, 5, -5, 7, -7, 9, -9, 11, -11, 13, -13, 15, -15},
+        [9  /*TCA*/] = {1, 3, 5, 7, 9, 11, 13, 15, -15, -13, -11, -9, -7, -5, -3, -1},
+        [10 /*OGA*/] = {-15, -13, -9, -11, -1, -3, -7, -5, 15, 13, 9, 11, 1, 3, 7, 5},
+    };
+
+    template <typename T>
+    inline T five_bit_look_up[11][32]
+    {
+        [0] = {},
+        [1   /*OB*/] = {-16, -15, -14, -13, -12, -11, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
+        [2   /*SM*/] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, -1, -2, -3, -4, -5, -6, -7, -8, -9, -10, -11, -12, -13, -14, -15},
+        [3   /*MS*/] = {0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 1, -1},
+        [4   /*TC*/] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, -16, -15, -14, -13, -12, -11, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1},
+        [5   /*OG*/] = {-16, -15, -13, -14, -9, -10, -12, -11, -1, -2, -4, -3, -8, -7, -5, -6, 15, 14, 12, 13, 8, 9, 11, 10, 0, 1, 3, 2, 7, 6, 4, 5},
+        [6  /*OBA*/] = {-31, -29, -27, -25, -23, -21, -19, -17, -15, -13, -11, -9, -7, -5, -3, -1, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31},
+        [7  /*SMA*/] = {1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, -1, -3, -5, -7, -9, -11, -13, -15, -17, -19, -21, -23, -25, -27, -29, -31},
+        [8  /*MSA*/] = {1, -1, 3, -3, 5, -5, 7, -7, 9, -9, 11, -11, 13, -13, 15, -15, 17, -17, 19, -19, 21, -21, 23, -23, 25, -25, 27, -27, 29, -29, 31, -31},
+        [9  /*TCA*/] = {1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, -31, -29, -27, -25, -23, -21, -19, -17, -15, -13, -11, -9, -7, -5, -3, -1},
+        [10 /*OGA*/] = {-31, -29, -25, -27, -17, -19, -23, -21, -1, -3, -7, -5, -15, -13, -9, -11, 31, 29, 25, 27, 17, 19, 23, 21, 1, 3, 7, 5, 15, 13, 9, 11},
+    };
+}
+
+#endif //ION_GSM_STREAM_ENCODINGS_H