X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=filter.c;h=f98b290ca4e282892861ecd5acc024d046802565;hb=50985c2019b2b5a6ce394589d89ee925b4f5e3a9;hp=80cef6abc47fc67f0f546148f85993a9a851f3e9;hpb=60eb1eb5820be30671729c08b371b0ab3c14c860;p=libsigrok.git diff --git a/filter.c b/filter.c index 80cef6ab..f98b290c 100644 --- a/filter.c +++ b/filter.c @@ -1,7 +1,7 @@ /* - * This file is part of the sigrok project. + * This file is part of the libsigrok project. * - * Copyright (C) 2010 Bert Vermeulen + * Copyright (C) 2010-2012 Bert Vermeulen * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -20,7 +20,32 @@ #include #include #include -#include +#include +#include "libsigrok.h" +#include "libsigrok-internal.h" + +/* Message logging helpers with driver-specific prefix string. */ +#define DRIVER_LOG_DOMAIN "filter: " +#define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args) +#define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args) +#define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args) +#define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args) +#define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args) +#define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args) + +/** + * @file + * + * Helper functions to filter out unused probes from samples. + */ + +/** + * @defgroup grp_filter Probe filter + * + * Helper functions to filter out unused probes from samples. + * + * @{ + */ /** * Remove unused probes from samples. @@ -29,31 +54,94 @@ * it -- to a sample taking up only as much space as required, with * unused probes removed. * - * @param in_unitsize The unit size of the input (data_in). - * @param out_unitsize The unit size of the output (data_out). - * @param probelist Pointer to a list of integers (probe numbers). - * @param data_in The input data. - * @param length_in The input data length. - * @param data_out The output data. - * @param length_out The output data length. - * @return SR_OK upon success, SR_ERR_MALLOC upon memory allocation errors. + * The "unit size" is the number of bytes used to store probe values. + * For example, a unit size of 1 means one byte is used (which can store + * 8 probe values, each of them is 1 bit). A unit size of 2 means we can + * store 16 probe values, 3 means we can store 24 probe values, and so on. + * + * If the data coming from the logic analyzer has a unit size of 4 for + * example (as the device has 32 probes), but only 2 of them are actually + * used in an acquisition, this function can convert the samples to only + * use up 1 byte per sample (unit size = 1) instead of 4 bytes per sample. + * + * The output will contain the probe values in the order specified via the + * probelist. For example, if in_unitsize = 4, probelist = [5, 16, 30], and + * out_unitsize = 1, then the output samples (each of them one byte in size) + * will have the following format: bit 0 = value of probe 5, bit 1 = value + * of probe 16, bit 2 = value of probe 30. Unused bit(s) in the output byte(s) + * are zero. + * + * The caller must make sure that length_in is not bigger than the memory + * actually allocated for the input data (data_in), as this function does + * not check that. + * + * @param in_unitsize The unit size (>= 1) of the input (data_in). + * @param out_unitsize The unit size (>= 1) the output shall have (data_out). + * The requested unit size must be big enough to hold as + * much data as is specified by the number of enabled + * probes in 'probelist'. + * @param probe_array Pointer to a list of probe numbers, numbered starting + * from 0. The list is terminated with -1. + * @param data_in Pointer to the input data buffer. Must not be NULL. + * @param length_in The input data length (>= 1), in number of bytes. + * @param data_out Variable which will point to the newly allocated buffer + * of output data. The caller is responsible for g_free()'ing + * the buffer when it's no longer needed. Must not be NULL. + * @param length_out Pointer to the variable which will contain the output + * data length (in number of bytes) when the function + * returns SR_OK. Must not be NULL. + * + * @return SR_OK upon success, SR_ERR_MALLOC upon memory allocation errors, + * or SR_ERR_ARG upon invalid arguments. + * If something other than SR_OK is returned, the values of + * out_unitsize, data_out, and length_out are undefined. + * + * @since 0.1.0 (but the API changed in 0.2.0) */ -int sr_filter_probes(int in_unitsize, int out_unitsize, int *probelist, - const unsigned char *data_in, uint64_t length_in, - char **data_out, uint64_t *length_out) +SR_API int sr_filter_probes(unsigned int in_unitsize, unsigned int out_unitsize, + const GArray *probe_array, const uint8_t *data_in, + uint64_t length_in, uint8_t **data_out, + uint64_t *length_out) { unsigned int in_offset, out_offset; - int num_enabled_probes, out_bit, i; + int *probelist, out_bit; + unsigned int i; uint64_t sample_in, sample_out; - if (!(*data_out = malloc(length_in))) - return SR_ERR_MALLOC; + if (!probe_array) { + sr_err("%s: probe_array was NULL", __func__); + return SR_ERR_ARG; + } + probelist = (int *)probe_array->data; + + if (!data_in) { + sr_err("%s: data_in was NULL", __func__); + return SR_ERR_ARG; + } + + if (!data_out) { + sr_err("%s: data_out was NULL", __func__); + return SR_ERR_ARG; + } - num_enabled_probes = 0; - for (i = 0; probelist[i]; i++) - num_enabled_probes++; + if (!length_out) { + sr_err("%s: length_out was NULL", __func__); + return SR_ERR_ARG; + } + + /* Are there more probes than the target unit size supports? */ + if (probe_array->len > out_unitsize * 8) { + sr_err("%s: too many probes (%d) for the target unit " + "size (%d)", __func__, probe_array->len, out_unitsize); + return SR_ERR_ARG; + } - if (num_enabled_probes == in_unitsize * 8) { + if (!(*data_out = g_try_malloc(length_in))) { + sr_err("%s: data_out malloc failed", __func__); + return SR_ERR_MALLOC; + } + + if (probe_array->len == in_unitsize * 8) { /* All probes are used -- no need to compress anything. */ memcpy(*data_out, data_in, length_in); *length_out = length_in; @@ -65,8 +153,8 @@ int sr_filter_probes(int in_unitsize, int out_unitsize, int *probelist, while (in_offset <= length_in - in_unitsize) { memcpy(&sample_in, data_in + in_offset, in_unitsize); sample_out = out_bit = 0; - for (i = 0; probelist[i]; i++) { - if (sample_in & (1 << (probelist[i] - 1))) + for (i = 0; i < probe_array->len; i++) { + if (sample_in & (1 << (probelist[i]))) sample_out |= (1 << out_bit); out_bit++; } @@ -78,3 +166,5 @@ int sr_filter_probes(int in_unitsize, int out_unitsize, int *probelist, return SR_OK; } + +/** @} */