diff --git a/src/alsadoc.md b/src/alsadoc.md
index 1d1cb00..0c7c513 100644
--- a/src/alsadoc.md
+++ b/src/alsadoc.md
@@ -1,13 +1,54 @@
+Title: Unofficial ALSA API documentation
+Author: Alessandro Mauri
+
# Unofficial ALSA API documentation
ALSA has to be the **worst** documented API in the whole FOSS world, so since I
had to go trough the pain of reverse-engineering other programs I thought to save
you form the same pain. So I present to you the most half-hassed description of
the ALSA API on the interweb.
+Official links:
+
+* ALSA documentation [main page](https://www.alsa-project.org/alsa-doc/alsa-lib/index.html)
+ - The [PCM interface](https://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html)
+
+
+Unofficial links:
+
+* [Userspace documentaion](https://alsa.opensrc.org/)
+
## Functions
+All the functions I encountered and some documentation / explanation
+
+---
### Interfaces
-TODO
+[//]: # (TODO explain what interfaces are)
+
+---
+
+### Streams
+In ALSA a stream is the collection of audio data flowing from an application to
+a card (playback), or from a card to an application (capture).
+ALSA uses the ring buffer to store outgoing (playback) and incoming (capture,
+record) samples. There are two pointers being maintained to allow a precise
+communication between application and device; pointing to current processed
+sample by hardware and last processed sample by application.
+The modern audio chips allow to program the transfer time periods. It means that
+the stream of samples is divided to small chunks. Device acknowledges to
+application when the transfer of a chunk is complete.
+
+The type of stream (or the direction in which sound is flowing) can be either
+capture or playback and is determined by `snd_pcm_stream_t` which is defined as:
+
+```c
+typedef enum _snd_pcm_stream {
+ SND_PCM_STREAM_PLAYBACK = 0, // Playback stream
+ SND_PCM_STREAM_CAPTURE, // Capture stream
+ SND_PCM_STREAM_LAST = SND_PCM_STREAM_CAPTURE
+} snd_pcm_stream_t;
+```
+---
### Hints
Hints are names, descriptions and other information about sound cards, interfaces
@@ -112,3 +153,123 @@ int main (int argc, char *argv[])
return 0;
}
```
+
+---
+
+### PCMs
+PCM is an abbreviation for "Pulse Code Modulation". PCM is how digital audio is
+typically represented in a computer. The audio signal is represented by samples
+of its instantaneous amplitude taken at regular intervals the representation of
+each sample can take several forms.
+
+In ALSA we usually use the term PCM to refer to a **PCM device**, a PCM device
+is something like an abstract soundcard. It can either be a hardware device or a
+PCM plugin layer device (like dmix, softvol, etc).
+
+#### Open modes
+**Blocking mode (0)**: when opening a PCM in blocked (which is the default mode)
+the behaviour is that if the resources are already in use with another
+application, then it blocks the caller, until resources are free.
+
+**Non blocking mode (SND_PCM_NONBLOCK)**: the non-blocked mode doesn't block the
+caller in any way and instead returns `-EBUSY` (that is `EBUSY * -1`) error when
+the resources are not available.
+
+**Asynchronous mode (SND_PCM_ASYNC)**:
+
+The opening modes affect all the standard I/O operations (such as writing), in
+the same way the options operate with `open(2)` and `write(2)`, so instead of
+making the calling process wait when the resource is not available, operations
+return `-EAGAIN /* EAGAIN * -1 */`, which literally means resource temporarly
+unavailable. The operation mode for successive (to opening) I/O calls can be
+changed with the `snd_pcm_nonblock()` function.
+
+In ALSA PCM devices are controlled trough handles, which are basically pointers
+to a data structure `snd_pcm_t` that defines it
+
+```c
+typedef struct _snd_pcm {
+ char *name;
+ snd_pcm_type_t type;
+ int stream;
+ int mode;
+ int poll_fd;
+ int setup;
+ unsigned int access; /* access mode */
+ unsigned int format; /* SND_PCM_FORMAT_* */
+ unsigned int subformat; /* subformat */
+ unsigned int rate; /* rate in Hz */
+ unsigned int channels; /* channels */
+ size_t fragment_size; /* fragment size */
+ unsigned int fragments; /* fragments */
+ unsigned int start_mode; /* start mode */
+ unsigned int ready_mode; /* ready detection mode */
+ unsigned int xrun_mode; /* xrun detection mode */
+ size_t avail_min; /* min avail frames for wakeup */
+ size_t xfer_min; /* xfer min size */
+ size_t xfer_align; /* xfer size need to be a multiple */
+ unsigned int time: 1; /* timestamp switch */
+ size_t boundary; /* pointers wrap point */
+ unsigned int info; /* Info for returned setup */
+ unsigned int msbits; /* used most significant bits */
+ unsigned int rate_master; /* Exact rate is rate_master / */
+ unsigned int rate_divisor; /* rate_divisor */
+ size_t fifo_size; /* chip FIFO size in frames */
+ size_t buffer_size;
+ size_t bits_per_sample;
+ size_t bits_per_frame;
+ size_t *appl_ptr;
+ volatile size_t *hw_ptr;
+ int mmap_rw;
+ snd_pcm_channel_info_t *mmap_channels;
+ snd_pcm_channel_area_t *running_areas;
+ snd_pcm_channel_area_t *stopped_areas;
+ void *stopped;
+ snd_pcm_ops_t *ops;
+ snd_pcm_fast_ops_t *fast_ops;
+ snd_pcm_t *op_arg;
+ snd_pcm_t *fast_op_arg;
+ void *private;
+} snd_pcm_t;
+```
+
+That's a lot of stuff but luckly we have functions to operate on this struct.
+
+#### `snd_pcm_open`
+Open a pcm returning it's handle that is pointer to it's defining data structure,
+`snd_pcm_t`
+
+```c
+int snd_pcm_open (snd_pcm_t **pcmp, const char *name, snd_pcm_stream_t stream, int mode);
+```
+
+ARGS:
+
+* `(const char)name`: PCM name identifier
+* `(snd_pcm_stream_t)stream`: wanted stream
+* `(int)mode`: mode of opening, valid modes are
+ - 0: blocking mode
+ - SND_PCM_NONBLOCK: non blocking mode
+ - SND_PCM_ASYNC: async notification mode
+
+RESULT:
+
+* `(snd_pcm_t)pcmp`: PCM handle, link to the PCM's defining struct. After use
+the handle should be passed to `snd_pcm_close()` to close and free the resources.
+
+RETURN: `(int)` 0 on success or negative code on error
+
+#### `snd_pcm_close`
+Close a PCM handle freeing the allocated resources
+
+```c
+int snd_pcm_close (snd_pcm_t *pcm);
+```
+
+ARGS:
+
+* `(snd_pcm_t *)pcm`: the PCM handle to close
+
+RESULT: RETURN: `(int)` 0 on success or negative code on error
+
+#### `snd_pcm_nonblock`
diff --git a/src/commonsizes.md b/src/commonsizes.md
index 995ef09..7b95751 100644
--- a/src/commonsizes.md
+++ b/src/commonsizes.md
@@ -1,3 +1,6 @@
+Title: Size in loc of common software
+Author: Alessandro Mauri
+
# Size in loc of common software
Bloat is everywhere, in 2018 I started my journey on debloating my digital
life, so far I mostly use linux as my main OS (the mostly is due to uni
diff --git a/src/index.md b/src/index.md
index 5a05ec0..f4d028e 100644
--- a/src/index.md
+++ b/src/index.md
@@ -1,11 +1,4 @@
-# Mauri's blog lol
-
----
-
-## Articles
+Title: Mauri's blog homepage
+Author: Alessandro Mauri
-[Size in loc of common software](commonsizes.html)
-
-[Programs I would like to see made/remade](makesoftware.html)
-
-[Unofficial ALSA documentation](alsadoc.html)
+# Mauri's blog lol
diff --git a/src/makesoftware.md b/src/makesoftware.md
index e7be1aa..ea48022 100644
--- a/src/makesoftware.md
+++ b/src/makesoftware.md
@@ -1,3 +1,6 @@
+Title: Programs someone should make
+Author: Alessandro Mauri
+
# Programs that I'd like to see made/remade
Most small utilities have already been made, and most big programs are perhaps
too big even for a small team, moreover old software has a lot of historical
diff --git a/src/styles.css b/src/styles.css
index 93bb020..7e5fc31 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -1,10 +1,34 @@
-/* Global options */
+/* GLOBAL */
* {
text-align: left;
- font-family: monospace;
+ font-family: sans-serif;
+}
+
+:root {
+ --bg: #282828;
+ --bg-code: #1d2021;
+ --bg-alt: #32302f;
+ --fg: #ebdbb2;
+ --fg-code: #fbf1c7;
+ --fg-alt: #d5c4a1;
+
+ --fg-link: #d79921;
+}
+
+body {
+ width: 50%;
+ margin: 0 auto;
+ background-color: var(--bg);
+ color: var(--fg);
+ padding: 10px;
+}
+
+html {
+/* background-color: #696969;*/
+ scroll-behavior: smooth;
}
-/* Table styles */
+/* TABLES */
table, th, td {
margin-left: auto;
margin-right: auto;
@@ -21,64 +45,63 @@ th, td {
}
th {
- border-bottom: 1px solid black;
+ border-bottom: 1px solid var(--fg);
}
tr:nth-child(odd) {
- background-color: #dcdcdc;
+ background-color: var(--bg-alt);
}
-/* Code style */
+/* CODE */
pre {
- background-color: #282828;
- color: #ebdbb2;
- padding: 2px;
- font-size: 14;
+ background-color: var(--bg-code);
+ color: var(--fg-code);
+ padding: 4px;
+ font-size: 15;
font-family: monospace;
tab-size: 8;
}
-
+/*
:not(pre) > code {
background-color: #f9f4d7;
color: #504945;
}
+*/
-/* List styles */
+/* LISTS */
li {
font-size: 14;
}
-/* Paragraphs and text */
+/* PARAGRAPHS */
p {
- font-size: 16;
+ font-size: 17;
padding-left: 20px;
padding-right: 20px;
}
-body {
- width: 50%;
- margin: 0 auto;
- background-color: #f5fffa;
- color: black;
- padding: 10px;
+/* HEADINGS */
+h1, h3, h5 {
+ text-decoration: underline;
}
-html {
-/* background-color: #696969;*/
- scroll-behavior: smooth;
+h2, h4, h6 {
+ background-color: var(--bg-alt);
}
-/* Headings and footer */
-h1 {
- text-decoration: underline;
-}
-/*
-h1, h2, h3, h4, h5, h6 {
- text-align: center;
+h1 { font-size: 35; }
+h2 { font-size: 30; }
+h3 { font-size: 25; }
+h4, h5, h6 { font-size: 20; }
+
+/* LINKS */
+a {
+ color: var(--fg-link);
}
-*/
+
+/* FOOTER */
footer {
- border: 1px solid black;
+ border: 1px solid var(--fg);
}
footer p {
@@ -87,7 +110,7 @@ footer p {
font-size: 12;
}
-/* Header style */
+/* HEADER */
#thumb {
position: absolute;
border-radius: 50%;
@@ -125,7 +148,7 @@ footer p {
height: 80px;
text-align: left;
line-height: 80px;
- font-size: 16;
- border: 1px solid black;
+ font-size: 17;
+ border: 1px solid var(--fg);
overflow: hidden;
}