etisnoop: add support for streamed and framed ETI files

1 files changed, 197 insertions, 0 deletions

diff --git a/etiinput.cpp b/etiinput.cpp
new file mode 100644
index 0000000..ea3241f
--- /dev/null
+++ b/etiinput.cpp
@@ -0,0 +1,197 @@
+/*
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
+   Her Majesty the Queen in Right of Canada (Communications Research
+   Center Canada)
+
+   Copyrigth (C) 2014
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+   Taken from ODR-DabMod
+
+   Supported file formats: RAW, FRAMED, STREAMED
+   Supports re-sync to RAW ETI file
+ */
+/*
+   This file is part of ODR-DabMod.
+
+   ODR-DabMod is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as
+   published by the Free Software Foundation, either version 3 of the
+   License, or (at your option) any later version.
+
+   ODR-DabMod is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with ODR-DabMod.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "etiinput.h"
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>           /* Definition of AT_* constants */
+#include <sys/stat.h>
+
+int identify_eti_format(FILE* inputFile, int *streamType)
+{
+    *streamType = ETI_STREAM_TYPE_NONE;
+
+    struct stat inputFileStat;
+    fstat(fileno(inputFile), &inputFileStat);
+    size_t inputfilelength_ = inputFileStat.st_size;
+
+    int nbframes_;
+
+    uint32_t sync;
+    uint32_t nbFrames;
+    uint16_t frameSize;
+
+    char discard_buffer[6144];
+
+    if (fread(&sync, sizeof(sync), 1, inputFile) != 1) {
+        fprintf(stderr, "Unable to read sync in input file!\n");
+        perror("");
+        return -1;
+    }
+    if ((sync == 0x49c5f8ff) || (sync == 0xb63a07ff)) {
+        *streamType = ETI_STREAM_TYPE_RAW;
+        if (inputfilelength_ > 0) {
+            nbframes_ = inputfilelength_ / 6144;
+        }
+        else {
+            nbframes_ = ~0;
+        }
+        if (fseek(inputFile, -sizeof(sync), SEEK_CUR) != 0) {
+            // if the seek fails, consume the rest of the frame
+            if (fread(discard_buffer, 6144 - sizeof(sync), 1, inputFile)
+                    != 1) {
+                fprintf(stderr, "Unable to read from input file!\n");
+                perror("");
+                return -1;
+            }
+        }
+        return 0;
+    }
+
+    nbFrames = sync;
+    if (fread(&frameSize, sizeof(frameSize), 1, inputFile) != 1) {
+        fprintf(stderr, "Unable to read frame size in input file!\n");
+        perror("");
+        return -1;
+    }
+    sync >>= 16;
+    sync &= 0xffff;
+    sync |= ((uint32_t)frameSize) << 16;
+
+    if ((sync == 0x49c5f8ff) || (sync == 0xb63a07ff)) {
+        *streamType = ETI_STREAM_TYPE_STREAMED;
+        frameSize = nbFrames & 0xffff;
+        if (inputfilelength_ > 0) {
+            nbframes_ = inputfilelength_ / (frameSize + 2);
+        }
+        else {
+            nbframes_ = ~0;
+        }
+        if (fseek(inputFile, -6, SEEK_CUR) != 0) {
+            // if the seek fails, consume the rest of the frame
+            if (fread(discard_buffer, frameSize - 4, 1, inputFile)
+                    != 1) {
+                fprintf(stderr, "Unable to read from input file!\n");
+                perror("");
+                return -1;
+            }
+        }
+        return 0;
+    }
+
+    if (fread(&sync, sizeof(sync), 1, inputFile) != 1) {
+        fprintf(stderr, "Unable to read nb frame in input file!\n");
+        perror("");
+        return -1;
+    }
+    if ((sync == 0x49c5f8ff) || (sync == 0xb63a07ff)) {
+        *streamType = ETI_STREAM_TYPE_FRAMED;
+        if (fseek(inputFile, -6, SEEK_CUR) != 0) {
+            // if the seek fails, consume the rest of the frame
+            if (fread(discard_buffer, frameSize - 4, 1, inputFile)
+                    != 1) {
+                fprintf(stderr, "Unable to read from input file!\n");
+                perror("");
+                return -1;
+            }
+        }
+        nbframes_ = ~0;
+        return 0;
+    }
+
+    // Search for the sync marker byte by byte
+    for (size_t i = 10; i < 6144 + 10; ++i) {
+        sync >>= 8;
+        sync &= 0xffffff;
+        if (fread((uint8_t*)&sync + 3, 1, 1, inputFile) != 1) {
+            fprintf(stderr, "Unable to read from input file!\n");
+            perror("");
+            return -1;
+        }
+        if ((sync == 0x49c5f8ff) || (sync == 0xb63a07ff)) {
+            *streamType = ETI_STREAM_TYPE_RAW;
+            if (inputfilelength_ > 0) {
+                nbframes_ = (inputfilelength_ - i) / 6144;
+            }
+            else {
+                nbframes_ = ~0;
+            }
+            if (fseek(inputFile, -sizeof(sync), SEEK_CUR) != 0) {
+                if (fread(discard_buffer, 6144 - sizeof(sync), 1, inputFile)
+                        != 1) {
+                    fprintf(stderr, "Unable to read from input file!\n");
+                    perror("");
+                    return -1;
+                }
+            }
+            return 0;
+        }
+    }
+
+    fprintf(stderr, "Bad input file format!\n");
+    return -1;
+}
+
+int get_eti_frame(FILE* inputfile, int stream_type, void* buf)
+{
+    // Initialise buffer
+    memset(buf, 0x55, 6144);
+
+    uint16_t frameSize;
+    if (stream_type == ETI_STREAM_TYPE_RAW) {
+        frameSize = 6144;
+    }
+    else {
+        if (fread(&frameSize, sizeof(frameSize), 1, inputfile) != 1) {
+            // EOF
+            return 0;
+        }
+    }
+
+    if (frameSize > 6144) { // there might be a better limit
+        printf("Wrong frame size %u in ETI file!\n", frameSize);
+        return -1;
+    }
+
+    int read_bytes = fread(buf, 1, frameSize, inputfile);
+    if (read_bytes != frameSize) {
+        // A short read of a frame (i.e. reading an incomplete frame)
+        // is not tolerated. Input files must not contain incomplete frames
+        printf("Incomplete frame in ETI file!\n");
+        return -1;
+    }
+
+    // We have added padding, so we always return 6144 bytes
+    return 6144;
+}
+