Add libvlc input

1 files changed, 201 insertions, 0 deletions

diff --git a/vlc_input.c b/vlc_input.c
new file mode 100644
index 0000000..fab8273
--- /dev/null
+++ b/vlc_input.c
@@ -0,0 +1,201 @@
+#include <stdlib.h>
+#include <pthread.h>
+#include <assert.h>
+#include <unistd.h>
+#include <string.h>
+#include "vlc_input.h"
+
+
+libvlc_instance_t     *m_vlc;
+libvlc_media_player_t *m_mp;
+
+unsigned int vlc_rate;
+
+struct vlc_buffer *head_buffer;
+
+pthread_mutex_t buffer_lock = PTHREAD_MUTEX_INITIALIZER;
+
+struct vlc_buffer* vlc_buffer_new()
+{
+    struct vlc_buffer* node;
+    node = malloc(sizeof(struct vlc_buffer));
+    memset(node, 0, sizeof(struct vlc_buffer));
+    return node;
+}
+
+void vlc_buffer_free(struct vlc_buffer* node)
+{
+    if (node->buf) {
+        free(node->buf);
+    }
+
+    free(node);
+}
+
+size_t vlc_buffer_totalsize(struct vlc_buffer* node)
+{
+    size_t totalsize = 0;
+    for (; node != NULL; node = node->next) {
+        totalsize += node->size;
+    }
+
+    return totalsize;
+}
+
+// VLC Audio prerender callback, we must allocate a buffer here
+void prepareRender(
+        void* p_audio_data,
+        uint8_t** pp_pcm_buffer,
+        size_t size)
+{
+    *pp_pcm_buffer = malloc(size);
+    return;
+}
+
+
+
+// Audio postrender callback
+void handleStream(
+        void* p_audio_data,
+        uint8_t* p_pcm_buffer,
+        unsigned int channels,
+        unsigned int rate,
+        unsigned int nb_samples,
+        unsigned int bits_per_sample,
+        size_t size,
+        int64_t pts)
+{
+    assert(channels == 2);
+    assert(rate == vlc_rate);
+    assert(bits_per_sample == 16);
+
+    const size_t max_length = 4 * size;
+
+    for (;;) {
+        pthread_mutex_lock(&buffer_lock);
+
+        if (vlc_buffer_totalsize(head_buffer) < max_length) {
+            struct vlc_buffer* newbuf = vlc_buffer_new();
+
+            newbuf->buf = p_pcm_buffer;
+            newbuf->size = size;
+
+            // Append the new buffer to the end of the linked list
+            struct vlc_buffer* tail = head_buffer;
+            while (tail->next) {
+                tail = tail->next;
+            }
+            tail->next = newbuf;
+
+            pthread_mutex_unlock(&buffer_lock);
+            return;
+        }
+
+        pthread_mutex_unlock(&buffer_lock);
+        usleep(100);
+    }
+}
+
+int vlc_in_prepare(unsigned verbosity, unsigned int rate, const char* uri)
+{
+    int err;
+    fprintf(stderr, "Initialising VLC...\n");
+
+    vlc_rate = rate;
+
+    // VLC options
+    char smem_options[512];
+    snprintf(smem_options, sizeof(smem_options),
+            "#transcode{acodec=s16l,samplerate=%d}:"
+            // We are using transcode because smem only support raw audio and
+            // video formats
+            "smem{"
+                "audio-postrender-callback=%lld,"
+                "audio-prerender-callback=%lld"
+            "}",
+            vlc_rate,
+            (long long int)(intptr_t)(void*)&handleStream,
+            (long long int)(intptr_t)(void*)&prepareRender);
+
+    char verb_options[512];
+    snprintf(verb_options, sizeof(verb_options),
+            "--verbose=%d", verbosity);
+
+    const char * const vlc_args[] = {
+        verb_options,
+        "--sout", smem_options // Stream to memory
+    };
+
+    // Launch VLC
+    m_vlc = libvlc_new(sizeof(vlc_args) / sizeof(vlc_args[0]), vlc_args);
+
+    // Load the media
+    libvlc_media_t *m;
+    m = libvlc_media_new_location(m_vlc, uri);
+    m_mp = libvlc_media_player_new_from_media(m);
+    libvlc_media_release(m);
+
+    // Allocate the list
+    head_buffer = vlc_buffer_new();
+
+    // Start playing
+    libvlc_media_player_play(m_mp);
+
+    fprintf(stderr, "VLC launched.\n");
+    return 0;
+}
+
+size_t vlc_in_read(void *buf, size_t len)
+{
+    size_t requested = len;
+    for (;;) {
+        pthread_mutex_lock(&buffer_lock);
+
+        if (vlc_buffer_totalsize(head_buffer) >= len) {
+            while (len >= head_buffer->size) {
+                if (head_buffer->buf) {
+                    // Get all the data from this list element
+                    memcpy(buf, head_buffer->buf, head_buffer->size);
+
+                    buf += head_buffer->size;
+                    len -= head_buffer->size;
+                }
+
+                if (head_buffer->next) {
+                    struct vlc_buffer *next_head = head_buffer->next;
+                    vlc_buffer_free(head_buffer);
+                    head_buffer = next_head;
+                }
+                else {
+                    vlc_buffer_free(head_buffer);
+                    head_buffer = vlc_buffer_new();
+                    break;
+                }
+            }
+
+            if (len > 0) {
+                assert(len < head_buffer->size);
+
+                memcpy(buf, head_buffer->buf, len);
+
+                // split the current head into two parts
+                size_t remaining = head_buffer->size - len;
+                uint8_t *newbuf = malloc(remaining);
+
+                memcpy(newbuf, head_buffer->buf + len, remaining);
+                free(head_buffer->buf);
+                head_buffer->buf = newbuf;
+                head_buffer->size = remaining;
+            }
+
+            pthread_mutex_unlock(&buffer_lock);
+            return requested;
+        }
+
+        pthread_mutex_unlock(&buffer_lock);
+        usleep(100);
+    }
+
+    abort();
+}
+