From: Camel Guo camelg@axis.com

In order for external software components to adjust ladspa plugin dynamically, this commit adds an option to exposes the control array of input control ports of a ladspa plugin to a file, through which any applications with proper permission can control this plugin.

Signed-off-by: Camel Guo camelg@axis.com --- src/pcm/pcm_ladspa.c | 157 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 139 insertions(+), 18 deletions(-)

diff --git a/src/pcm/pcm_ladspa.c b/src/pcm/pcm_ladspa.c index ad73347d..40b5d38f 100644 --- a/src/pcm/pcm_ladspa.c +++ b/src/pcm/pcm_ladspa.c @@ -32,6 +32,9 @@ * http://www.medianet.ag */

+#include <stdbool.h> +#include <sys/mman.h> +#include <sys/stat.h> #include <dirent.h> #include <locale.h> #include <math.h> @@ -93,7 +96,8 @@ typedef struct { unsigned int port_bindings_size; /* size of array */ unsigned int *port_bindings; /* index = channel number, value = LADSPA port */ unsigned int controls_size; /* size of array */ - unsigned char *controls_initialized; /* initialized by ALSA user */ + bool controls_new; /* if controls is new, it can be overrided by alsa config */ + bool controls_shared; /* if controls is shared memory map */ LADSPA_Data *controls; /* index = LADSPA control port index */ } snd_pcm_ladspa_plugin_io_t;

@@ -101,6 +105,7 @@ typedef struct { struct list_head list; snd_pcm_ladspa_policy_t policy; char *filename; + char *controls_path; void *dl_handle; const LADSPA_Descriptor *desc; snd_pcm_ladspa_plugin_io_t input; @@ -110,6 +115,73 @@ typedef struct {

#endif /* DOC_HIDDEN */

+static LADSPA_Data* mmap_ladspa_controls(const char* filename, unsigned long length, bool *is_new) +{ + LADSPA_Data *ptr = NULL; + int fd = -1; + int ret = 0; + struct stat statbuf = { 0 }; + int prot = PROT_READ; + + if (filename == NULL || is_new == NULL) return NULL; + + *is_new = false; + + fd = open(filename, O_RDONLY); + if(fd < 0) { + if (errno == ENOENT) { + fd = open(filename, O_RDWR | O_CREAT, 0666); + if(fd < 0) { + SNDERR("Failed to open controls file: %s", filename); + return NULL; + } + + prot |= PROT_WRITE; + *is_new = true; + } else { + SNDERR("Failed to open %s due to '%s'", filename, strerror(errno)); + return NULL; + } + } + + ret = fstat(fd, &statbuf); + if (ret == -1) { + SNDERR("Failed to get status of '%s' due to '%s'", filename, strerror(errno)); + goto out; + } + + if (statbuf.st_size < (off_t) length) { + /* this file is invalid, must be truncated and re-initialized later on */ + close(fd); + + fd = open(filename, O_RDWR | O_CREAT, 0666); + if(fd < 0) { + SNDERR("Failed to open controls file: %s", filename); + /* no need to close(fd), so just return */ + return NULL; + } + + ret = ftruncate(fd, length); + if (ret == -1) { + SNDERR("Failed to increase the size of '%s' due to '%s'", filename, strerror(errno)); + goto out; + } + + prot |= PROT_WRITE; + *is_new = true; + } + + ptr = (LADSPA_Data*) mmap(NULL, length, prot, MAP_SHARED, fd, 0); + if(ptr == MAP_FAILED) { + SNDERR("Failed to mmap %s due to %s", filename, strerror(errno)); + ptr = NULL; + } + +out: + close (fd); + return ptr; +} + static unsigned int snd_pcm_ladspa_count_ports(snd_pcm_ladspa_plugin_t *lplug, LADSPA_PortDescriptor pdesc) { @@ -174,8 +246,11 @@ static int snd_pcm_ladspa_find_port_idx(unsigned int *res,

static void snd_pcm_ladspa_free_io(snd_pcm_ladspa_plugin_io_t *io) { - free(io->controls); - free(io->controls_initialized); + if (io->controls_shared) { + munmap(io->controls, io->controls_size * sizeof(LADSPA_Data)); + } else { + free(io->controls); + } }

static void snd_pcm_ladspa_free_plugins(struct list_head *plugins) @@ -186,6 +261,8 @@ static void snd_pcm_ladspa_free_plugins(struct list_head *plugins) snd_pcm_ladspa_free_io(&plugin->output); if (plugin->dl_handle) dlclose(plugin->dl_handle); + if (plugin->controls_path) + free(plugin->controls_path); free(plugin->filename); list_del(&plugin->list); free(plugin); @@ -574,8 +651,6 @@ static int snd_pcm_ladspa_connect_controls(snd_pcm_ladspa_plugin_t *plugin, for (idx = midx = 0; idx < plugin->desc->PortCount; idx++) if ((plugin->desc->PortDescriptors[idx] & (io->pdesc | LADSPA_PORT_CONTROL)) == (io->pdesc | LADSPA_PORT_CONTROL)) { if (io->controls_size > midx) { - if (!io->controls_initialized[midx]) - snd_pcm_ladspa_get_default_cvalue(plugin->desc, idx, &io->controls[midx]); plugin->desc->connect_port(instance->handle, idx, &io->controls[midx]); } else { return -EINVAL; @@ -878,6 +953,10 @@ snd_pcm_ladspa_write_areas(snd_pcm_t *pcm, snd_pcm_ladspa_plugin_t *plugin = list_entry(pos, snd_pcm_ladspa_plugin_t, list); list_for_each(pos1, &plugin->instances) { instance = list_entry(pos1, snd_pcm_ladspa_instance_t, list); + if (plugin->input.controls_shared) { + (void) snd_pcm_ladspa_connect_controls(plugin, &plugin->input, instance); + } + /* Skip output controls since they can not be changed dynamically */ for (idx = 0; idx < instance->input.channels.size; idx++) { chn = instance->input.channels.array[idx]; data = instance->input.data[idx]; @@ -939,6 +1018,10 @@ snd_pcm_ladspa_read_areas(snd_pcm_t *pcm, snd_pcm_ladspa_plugin_t *plugin = list_entry(pos, snd_pcm_ladspa_plugin_t, list); list_for_each(pos1, &plugin->instances) { instance = list_entry(pos1, snd_pcm_ladspa_instance_t, list); + if (plugin->input.controls_shared) { + (void) snd_pcm_ladspa_connect_controls(plugin, &plugin->input, instance); + } + /* Skip output controls since they can not be changed dynamically */ for (idx = 0; idx < instance->input.channels.size; idx++) { chn = instance->input.channels.array[idx]; data = instance->input.data[idx]; @@ -1227,26 +1310,50 @@ static int snd_pcm_ladspa_add_default_controls(snd_pcm_ladspa_plugin_t *lplug, { unsigned int count = 0; LADSPA_Data *array; - unsigned char *initialized; unsigned long idx; + unsigned long midx; + bool controls_shared = false; + bool is_new = true;

for (idx = 0; idx < lplug->desc->PortCount; idx++) if ((lplug->desc->PortDescriptors[idx] & (io->pdesc | LADSPA_PORT_CONTROL)) == (io->pdesc | LADSPA_PORT_CONTROL)) count++; - array = (LADSPA_Data *)calloc(count, sizeof(LADSPA_Data)); - if (!array) - return -ENOMEM; - initialized = (unsigned char *)calloc(count, sizeof(unsigned char)); - if (!initialized) { - free(array); - return -ENOMEM; + + /* + * Only support to expose ladspa control array for input control ports + */ + if ((io->pdesc == LADSPA_PORT_INPUT) && lplug->controls_path && count != 0) { + array = mmap_ladspa_controls(lplug->controls_path, count * sizeof(LADSPA_Data), &is_new); + if (!array) + return -ENOMEM; + controls_shared = true; + } else { + array = (LADSPA_Data *)calloc(count, sizeof(LADSPA_Data)); + if (!array) + return -ENOMEM; + } + + if (is_new) { + /* + * Initialize array of controls of this ladspa plugin with its + * default values defined in this plugin implementation. This + * array can be overrided by its alsa configuration files. + */ + for (idx = midx = 0; idx < lplug->desc->PortCount; idx++) { + if ((lplug->desc->PortDescriptors[idx] & (io->pdesc | LADSPA_PORT_CONTROL)) == (io->pdesc | LADSPA_PORT_CONTROL)) { + snd_pcm_ladspa_get_default_cvalue(lplug->desc, idx, &array[midx]); + midx++; + } + } } + io->controls_size = count; - io->controls_initialized = initialized; + io->controls_new = is_new; + io->controls_shared = controls_shared; io->controls = array;

return 0; -} +}

static int snd_pcm_ladspa_parse_controls(snd_pcm_ladspa_plugin_t *lplug, snd_pcm_ladspa_plugin_io_t *io, @@ -1287,8 +1394,10 @@ static int snd_pcm_ladspa_parse_controls(snd_pcm_ladspa_plugin_t *lplug, SNDERR("internal error"); return err; } - io->controls_initialized[uval] = 1; - io->controls[uval] = (LADSPA_Data)dval; + + if (io->controls_new) { + io->controls[uval] = (LADSPA_Data)dval; + } }

return 0; @@ -1429,7 +1538,7 @@ static int snd_pcm_ladspa_add_plugin(struct list_head *list, int reverse) { snd_config_iterator_t i, next; - const char *label = NULL, *filename = NULL; + const char *label = NULL, *filename = NULL, *controls_path = NULL; long ladspa_id = 0; int err; snd_pcm_ladspa_plugin_t *lplug; @@ -1467,6 +1576,12 @@ static int snd_pcm_ladspa_add_plugin(struct list_head *list, output = n; continue; } + if (strcmp(id, "controls") == 0) { + err = snd_config_get_string(n, &controls_path); + if (err < 0) + return err; + continue; + } if (strcmp(id, "policy") == 0) { const char *str; err = snd_config_get_string(n, &str); @@ -1496,6 +1611,11 @@ static int snd_pcm_ladspa_add_plugin(struct list_head *list, lplug->input.pdesc = LADSPA_PORT_INPUT; lplug->output.pdesc = LADSPA_PORT_OUTPUT; INIT_LIST_HEAD(&lplug->instances); + if (controls_path) { + lplug->controls_path = strdup(controls_path); + } else { + lplug->controls_path = NULL; + } if (filename) { err = snd_pcm_ladspa_check_file(lplug, filename, label, ladspa_id); if (err < 0) { @@ -1692,6 +1812,7 @@ pcm.name { [label STR] # LADSPA plugin label (for example 'delay_5s') [filename STR] # Full filename of .so library with LADSPA plugin code [policy STR] # Policy can be 'none' or 'duplicate' + [controls STR] # Path (directory) with controls for this plugin input | output { bindings { C INT or STR # C - channel, INT - audio port index, STR - audio port name