Work in progress

lib/micro-rtsp-server/include/micro_rtsp_jpeg.h

@@ -2,17 +2,34 @@
 
 #include <stdint.h>
 #include <stddef.h>
-#include <tuple>
 
 class micro_rtsp_jpeg
 {
 public:
-    micro_rtsp_jpeg(const uint8_t *jpeg, size_t size);
+    bool decode_jpeg(const uint8_t *jpg, size_t size);
 
-    std::tuple<const uint8_t *, size_t> quantization_table_0_;
-    std::tuple<const uint8_t *, size_t> quantization_table_1_;
-    std::tuple<const uint8_t *, size_t> jpeg_data_;
-protected:
-    bool decode_jpeg(uint8_t *jpg, size_t size);
-    std::tuple<const uint8_t *, size_t> find_jpeg_section(uint8_t **ptr, uint8_t *end, uint8_t flag);
+    class __attribute__ ((packed)) jpg_section
+    {
+    public:
+        uint8_t flag() const { return section_flag; }
+        const char *flag_name() const;
+        uint16_t section_length() const { return section_flag == 0xd8 || section_flag == 0xd9 ? 0 : (section_length_msb << 8) + section_length_lsb; }
+        const uint8_t *data() const { return reinterpret_cast<const uint8_t *>(&section_data[1]); }
+        uint16_t data_length() const { return section_length() - 3; }
+
+    private:
+        const uint8_t section_flag;
+        const uint8_t section_length_msb;
+        const uint8_t section_length_lsb;
+        const uint8_t section_data[];
+    };
+
+    const jpg_section *quantization_table_0_;
+    const jpg_section *quantization_table_1_;
+
+    const uint8_t *jpeg_data_start;
+    const uint8_t *jpeg_data_end;
+
+private:
+    static const jpg_section *find_jpeg_section(const uint8_t **ptr, const uint8_t *end, uint8_t flag);
 };

lib/micro-rtsp-server/src/micro_rtsp_jpeg.cpp

@@ -2,100 +2,100 @@
 
 #include "micro_rtsp_jpeg.h"
 
-micro_rtsp_jpeg::micro_rtsp_jpeg(const uint8_t *jpeg, size_t size)
+const char *micro_rtsp_jpeg::jpg_section::flag_name() const
 {
+    switch (section_flag)
+    {
+    case 0xd8:
+        return "SOI"; // start of image
+    case 0xd9:
+        return "EOI"; // end of image
+    case 0xe0:
+        return "APP0";
+    case 0xdb:
+        return "DQT"; // define quantization table
+    case 0xc4:
+        return "DHT"; // define Huffman table
+    case 0xc0:
+        return "SOF"; // start of frame
+    case 0xda:
+        return "SOS"; // start of scan
+    }
+    return "Unknown";
 }
 
-std::tuple<const uint8_t *, size_t> micro_rtsp_jpeg::find_jpeg_section(uint8_t **ptr, uint8_t *end, uint8_t flag)
+const micro_rtsp_jpeg::jpg_section *micro_rtsp_jpeg::find_jpeg_section(const uint8_t **ptr, const uint8_t *end, uint8_t flag)
 {
-    size_t len;
+    log_d("find_jpeg_section 0x%02x", flag);
     while (*ptr < end)
     {
-        auto framing = *(*ptr++);
+        auto framing = *((*ptr)++);
         if (framing != 0xff)
         {
-            log_e("Malformed jpeg. Expected framing 0xff but found: 0x%02x", framing);
+            log_e("Expected framing 0xff but found: 0x%02x", framing);
             break;
         }
 
         // framing = 0xff, flag, len MSB, len LSB
-        auto flag_code = *(*ptr++);
-        // Length of section
-        len = *(*ptr++) * 256 + *(*ptr++);
-        if (flag_code == flag)
-            return std::tuple<const uint8_t *, size_t>(*ptr, len);
-
-        // Skip the section
-        switch (flag_code)
-        {
-        case 0xe0: // APP00
-        case 0xdb: // DQT (define quantization table)
-        case 0xc4: // DHT (define Huffman table)
-        case 0xc0: // SOF0 (start of frame)
-        case 0xda: // SOS (start of scan)
+        auto section = reinterpret_cast<const jpg_section *>((*ptr)++);
+        // Advance pointer section has a length, so not SOI (0xd8) and EOI (0xd9)
+        *ptr += section->section_length();
+        if (section->flag() == flag)
         {
-            log_d("Skipping jpeg section flag: 0x%02x, %d bytes", flag_code, len);
-            ptr += len;
-            break;
-        }
-        default:
-            log_e("Unexpected jpeg flag: 0x%02x", flag_code);
+            log_d("Found section 0x%02x (%s), %d bytes", flag, section->flag_name(), section->section_length());
+            return section;
         }
+
+        log_d("Skipping section: 0x%02x (%s), %d bytes", section->flag(), section->flag_name(), section->section_length());
     }
 
     // Not found
-    return std::tuple<const uint8_t *, size_t>(nullptr, 0);
+    return nullptr;
 }
 
 // See https://create.stephan-brumme.com/toojpeg/
-bool micro_rtsp_jpeg::decode_jpeg(uint8_t *data, size_t size)
+bool micro_rtsp_jpeg::decode_jpeg(const uint8_t *data, size_t size)
 {
+    log_d("decode_jpeg");
     // Look for start jpeg file (0xd8)
     auto ptr = data;
     auto end = ptr + size;
 
     // Check for SOI (start of image) 0xff, 0xd8
-    if (*(ptr++) != 0xff || *(ptr++) != 0xd8)
+    if (!find_jpeg_section(&ptr, end, 0xd8))
     {
         log_e("No valid start of image marker found");
         return false;
     }
 
     // First quantization table
-    quantization_table_0_ = find_jpeg_section(&ptr, end, 0xdb);
-    if (std::get<0>(quantization_table_0_) == nullptr)
-    {
+    if (!(quantization_table_0_ = find_jpeg_section(&ptr, end, 0xdb)))
         log_e("No quantization table 0 section found");
-    }
 
     // Second quantization table (for color images)
-    quantization_table_1_ = find_jpeg_section(&ptr, end, 0xdb);
-    if (std::get<0>(quantization_table_1_) == nullptr)
-    {
+    if (!(quantization_table_1_ = find_jpeg_section(&ptr, end, 0xdb)))
         log_w("No quantization table 1 section found");
-    }
+
     // Start of scan
-    auto sos = find_jpeg_section(&ptr, end, 0xda);
-    if (std::get<0>(sos) == nullptr)
-    {
+    if (!find_jpeg_section(&ptr, end, 0xda))
         log_e("No start of scan section found");
-    }
 
     // Start of the data sections
-    auto start = ptr;
+    jpeg_data_start = ptr;
+
     // Scan over all the sections. 0xff followed by not zero, is a new section
-    while (ptr < end - 1 && (*ptr != 0xff || ptr[1] == 0))
+    while (ptr < end - 1 && (ptr[0] != 0xff || ptr[1] == 0))
         ptr++;
 
-    // Go back tgo start of section
-    ptr--;
-
     // Check if marker is an end of image marker
-    if (*(ptr++) != 0xff || *(ptr++) != 0xd9)
+    if (!find_jpeg_section(&ptr, end, 0xd9))
     {
         log_e("No end of image marker found");
+        return false;
     }
 
-    jpeg_data_ = std::tuple<const uint8_t *, size_t>(start, size - (ptr - start - 2));
+    jpeg_data_end = ptr;
+    log_d("Total jpeg data = %d bytes", jpeg_data_end - jpeg_data_start);
+
     return true;
 }

platformio.ini

@@ -31,6 +31,7 @@ default_envs = esp32cam_ai_thinker
 [env]
 platform = espressif32
 framework = arduino
+test_framework = unity
 
 #upload_protocol = espota
 #upload_port = 192.168.178.223
@@ -42,7 +43,8 @@ framework = arduino
 monitor_speed = 115200
 monitor_rts = 0
 monitor_dtr = 0
-monitor_filters = log2file, time, default, esp32_exception_decoder
+#monitor_filters = log2file, time, default, esp32_exception_decoder
+monitor_filters = esp32_exception_decoder
 
 build_flags =
   -Ofast