Manu Abraham wrote:
> Henrik Sjoberg wrote:
>
>> Hi,
>>
>> This is a bit embarrassing, but my latest patch contained pmt test code,
>> which caused it not to work. I have prepared another one (third one's a
>> charm?) which I have actually tested against cvs dvb-apps. It works
>> ok for
>> me.
>>
>>
>>
>
> Any comments on this patch ? If none i can check it in.
>
>
> Manu
Yeah, minor comments... Should use space after keywords like "if"
and "for".
General comment about the code is that there are a lot of "magic numbers"
that aren't evident to the casual reader:
+ if(p_descriptor->descriptor_tag != 0x09) {
+ printf("ERROR::Trying to copy a CA descriptor with
incorrect tag [%d]. Bailing out.\n",
+ p_descriptor->descriptor_tag);
+ return 16;
+ }
It's not clear what 0x09 signifies here... This should be either a
"const unsigned"
or else a #define... Ditto for the 16...
There are no other printf()'s in this library... And errors should usually
go to STDERR anyway... But in general, a library should return error
status but not print messages. Let the application decide if it wants to
generate a message or not.
More comments...
+static void try_move_ca_descriptors(struct service_info *p_si)
+{
+ int i;
+ int j;
+ int k;
+ int l;
+ struct streams *p_stream1;
+ struct streams *p_stream2;
+ struct descriptor *p_desc1;
+ struct descriptor *p_desc2;
+ int movable = 1;
+ int ca_descriptors = 0;
+ int num_ca1;
+ int num_ca2;
+ int found_match;
+ int found;
Use commas and group variables of identical types.
Do we need:
+ //int j, k, l, i2, j2;
In:
printf("%s: Setting PMT Command\n", __FUNCTION__);
- for (i = 0; i < p_en50221_pmt_object->program_desc_count; i++) {
- if
(p_en50221_pmt_object->p_en50221_prog_desc[i].descriptor_tag
== 0x09) {
- printf("%s: CA descriptor found @ PROGRAM Level,
Setting CA PMT command=[%02x]\n", __FUNCTION__, pmt_command);
+ if (p_en50221_pmt_object->program_desc_count > 0) {
+ printf("%s: CA descriptor(s) found @ PROGRAM Level,
Setting CA PMT command=[%02x]\n",
+ __FUNCTION__, pmt_command);
p_en50221_pmt_object->ca_pmt_cmd_id = pmt_command;
object_length += 8;
}
- }
If you're changing the level of nesting, then the indent should change
as well...
In:
+ sprintf(message, "%s: %s={", __FUNCTION__, type);
+
+ sprintf(temp, "Length=%d", ptr[pos++]);
+ strcat(message, temp);
+ list_management = ptr[pos++];
+ sprintf(temp, ":CA_PMT_ListManagement=%d", list_management);
+ strcat(message, temp);
+ sprintf(temp, ":ProgramNumber=0x%02x%02x=%d", ptr[pos + 0],
+ ptr[pos + 1], (ptr[pos + 0] << 8) + ptr[pos + 1]);
+ strcat(message, temp);
+ pos += 2;
+ sprintf(temp, ":VersionNumber=%d", (ptr[pos++] >> 1) & 0x1f);
+ strcat(message, temp);
+ program_info_length = ((ptr[pos + 0] << 8) & 0x0f) + ptr[pos + 1];
+ pos += 2;
+ sprintf(temp, ":Program={");
+ strcat(message, temp);
I would set up a FILE * to point to the buffer, and therefore guard
against overflowing the size of the buffer. Looking a little further,
though, we see:
+ sprintf(temp, "}\n");
+ strcat(message, temp);
+
+ printf(message);
+
+ return 0;
So I'm stumped... Why all of this trouble to build a buffer and then
printf(), when it could be printf'd as you go?
Also, printf(message) is dangerous... What if "message" contains
"%s"? Should be using fputs(message, STDOUT) instead... And
that would avoid using:
+ char message[2048];
which is a lot of stack space.
Not sure why:
uint16_t debug_parse_message(struct ca_msg *p_ca_msg, uint16_t length)
needs a return value, if it's an invariant "0".
Regarding changes like:
+++ lib/libdvbsi/channels.c 18 Oct 2005 16:44:42 -0000
@@ -102,7 +102,6 @@
static int parse_param(char *val, const param *p_list, int list_size)
{
int i;
-
for (i = 0; i < list_size; i++) {
if (strcasecmp(p_list[i].name, val) == 0)
return p_list[i].value;
Please avoid whitespace only changes. They make merging multiple
branches hellish.
Also, many people like a blank line between declarations and statements.
Looking at:
+ if (p_descriptor->extended_event.length_of_items)
+ free(p_descriptor->extended_event.p_items);
+ if (p_descriptor->extended_event.text_length)
+ free(p_descriptor->extended_event.p_text_char);
Don't bother. free(NULL) is perfectly fine. I would, on the
other hand, always NULL out a pointer that I've freed, unless
it is about to go out of scope. I.e.:
free(p_description->extended_event.p_text_char);
p_description->extended_event.p_text_char = NULL;
and thus avoid memory leaks or double-frees. Same elsewhere.
In:
+ p_descriptor->short_event.iso_639_language_code =
+ (((buf[pos] << 8) | buf[pos + 1]) << 8) | buf[pos + 2];
Not sure I get this... Shouldn't "pos" be shifted more bits? Otherwise,
"pos" and "pos + 1" will be combined... Oh, got it. Didn't match parens.
Well, I'd still write:
(buf[pos] << 16) | (buf[pos + 1] << 8) | buf[pos + 2];
instead...
Regarding:
+ struct descriptor *p_en50221_streams_desc =
+ (struct descriptor *) malloc(sizeof (struct descriptor)
* p_streams->streams_desc_count);
malloc() returns a "void *", which is an untyped pointer. It doesn't need
to be cast. Also:
p = malloc(sizeof(*p));
is a lot more clear than:
p = malloc(sizeof(struct descriptor))
since you don't have to flip back and confirm that "p" is of type
"struct descriptor". Same applies whether you are allocating a
single element or an array of them.
In general, I'd avoid unnecessary typecasts, because they hide the
instances when you're actually changing the pointer type in the noise.
-Philip
