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Multichannel support (#37)
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* Support for multichannel in scream-pulse

* Support for multichannel

* Multichannel support for scream-alsa, minor changes in scream-pulse.

* Multichannel support for scream-raw

* New protocol support for ScreamReader, multichannel is supported but not channel mapping. Also fixed a null pointer exception if you try to change the volume before the first udp packet is received.

* Increased the number of chunks to fix the occasional hiccups when transmitting at high bitrates
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@martinellimarco @duncanthrax
martinellimarco authored and duncanthrax committed Apr 13, 2019
1 parent 3e88ba1 commit 0a6adfe
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Showing 16 changed files with 316 additions and 79 deletions.
116 changes: 100 additions & 16 deletions Receivers/alsa/scream-alsa.c
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Original file line number Diff line number Diff line change
Expand Up @@ -13,8 +13,9 @@
#define DEFAULT_MULTICAST_GROUP "239.255.77.77"
#define DEFAULT_PORT 4010

#define MAX_SO_PACKETSIZE 1154
#define CHANNELS 2
#define MAX_CHANNELS 8
#define HEADER_SIZE 5
#define MAX_SO_PACKETSIZE 1152+HEADER_SIZE

#define SNDCHK(call, ret) { \
if (ret < 0) { \
Expand Down Expand Up @@ -106,7 +107,7 @@ static int dump_alsa_info(snd_pcm_t *pcm)
return 0;
}

static int setup_alsa(snd_pcm_t **psnd, snd_pcm_format_t format, unsigned int rate, int verbosity, unsigned int target_latency_ms, const char *output_device)
static int setup_alsa(snd_pcm_t **psnd, snd_pcm_format_t format, unsigned int rate, int verbosity, unsigned int target_latency_ms, const char *output_device, int channels, snd_pcm_chmap_t **channel_map)
{
int ret;
int soft_resample = 1;
Expand All @@ -116,9 +117,21 @@ static int setup_alsa(snd_pcm_t **psnd, snd_pcm_format_t format, unsigned int ra
SNDCHK("snd_pcm_open", ret);

ret = snd_pcm_set_params(*psnd, format, SND_PCM_ACCESS_RW_INTERLEAVED,
CHANNELS, rate, soft_resample, latency);
channels, rate, soft_resample, latency);
SNDCHK("snd_pcm_set_params", ret);

ret = snd_pcm_set_chmap(*psnd, *channel_map);
if (ret == -ENXIO) { // snd_pcm_set_chmap returns -ENXIO if device does not support channel maps at all
if (channels > 2) { // but it's relevant only above 2 channels
fprintf(stderr, "Your device doesn't support channel maps. Channels may be in the wrong order.\n");
// TODO ALSA has a fixed channel order and we have the source channel_map.
// It's possible to reorder the channels in software. Maybe a place to start is the remap_data function in aplay.c
}
}
else {
SNDCHK("snd_pcm_set_chmap", ret);
}

if (verbosity > 0) {
return dump_alsa_info(*psnd);
}
Expand All @@ -134,14 +147,14 @@ static int close_alsa(snd_pcm_t *snd) {
return 0;
}

static int write_frames(snd_pcm_t *snd, unsigned char buf[MAX_SO_PACKETSIZE-2], int total_frames, int bytes_per_sample)
static int write_frames(snd_pcm_t *snd, unsigned char buf[MAX_SO_PACKETSIZE-HEADER_SIZE], int total_frames, int bytes_per_sample, int channels)
{
int i = 0;
int ret;
snd_pcm_sframes_t written;

while (i < total_frames) {
written = snd_pcm_writei(snd, &buf[i * bytes_per_sample * CHANNELS], total_frames - i);
written = snd_pcm_writei(snd, &buf[i * bytes_per_sample * channels], total_frames - i);
if (written < 0) {
ret = snd_pcm_recover(snd, written, 0);
SNDCHK("snd_pcm_recover", ret);
Expand Down Expand Up @@ -170,6 +183,16 @@ int main(int argc, char *argv[])
unsigned int rate = 44100;
unsigned char cur_server_rate = 0;
unsigned char cur_server_size = 0;
unsigned char cur_channels = 2;
unsigned char cur_channel_map_lsb = 0x03; // stereo
unsigned char cur_channel_map_msb = 0;
uint16_t cur_channel_map = (cur_channel_map_msb << 8) | cur_channel_map_lsb;

snd_pcm_chmap_t *channel_map;
channel_map = malloc(sizeof(snd_pcm_chmap_t) + MAX_CHANNELS*sizeof(unsigned int));
channel_map->channels = 2;
channel_map->pos[0] = SND_CHMAP_FL;
channel_map->pos[1] = SND_CHMAP_FR;

// Command line options
int use_unicast = 0;
Expand All @@ -179,7 +202,6 @@ int main(int argc, char *argv[])
int target_latency_ms = 50;
char *output_device ="default";


while ((opt = getopt(argc, argv, "i:g:p:t:vuho:")) != -1) {
switch (opt) {
case 'i':
Expand Down Expand Up @@ -208,13 +230,13 @@ int main(int argc, char *argv[])
show_usage(argv[0]);
}
}

if (optind < argc) {
fprintf(stderr, "Expected argument after options\n");
show_usage(argv[0]);
}

sockfd = socket(AF_INET, SOCK_DGRAM, 0);

memset((void *)&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = use_unicast ? interface : htonl(INADDR_ANY);
Expand All @@ -229,18 +251,22 @@ int main(int argc, char *argv[])
(const void *)&imreq, sizeof(struct ip_mreq));
}

if (setup_alsa(&snd, format, rate, verbosity, target_latency_ms, output_device) == -1) {
if (setup_alsa(&snd, format, rate, verbosity, target_latency_ms, output_device, cur_channels, &channel_map) == -1) {
return -1;
}

for (;;) {
n = recvfrom(sockfd, &buf, MAX_SO_PACKETSIZE, 0, NULL, 0);
if (n < 2) continue;
if (n < HEADER_SIZE) continue;

// Change rate/size?
if (cur_server_rate != buf[0] || cur_server_size != buf[1]) {
if (cur_server_rate != buf[0] || cur_server_size != buf[1] || cur_channels != buf[2] || cur_channel_map_lsb != buf[3] || cur_channel_map_msb != buf[4]) {
cur_server_rate = buf[0];
cur_server_size = buf[1];
cur_channels = buf[2];
cur_channel_map_lsb = buf[3];
cur_channel_map_msb = buf[4];
cur_channel_map = (cur_channel_map_msb << 8) | cur_channel_map_lsb;

rate = ((cur_server_rate >= 128) ? 44100 : 48000) * (cur_server_rate % 128);
switch (cur_server_size) {
Expand All @@ -253,23 +279,81 @@ int main(int argc, char *argv[])
rate = 0;
}

channel_map->channels = cur_channels;
if (cur_channels == 1) {
channel_map->pos[0] = SND_CHMAP_MONO;
}
else {
// k is the key to map a windows SPEAKER_* position to a PA_CHANNEL_POSITION_*
// it goes from 0 (SPEAKER_FRONT_LEFT) up to 10 (SPEAKER_SIDE_RIGHT) following the order in ksmedia.h
// the SPEAKER_TOP_* values are not used
int k = -1;
for (int i=0; i<cur_channels; i++) {
for (int j = k+1; j<=10; j++) {// check the channel map bit by bit from lsb to msb, starting from were we left on the previous step
if ((cur_channel_map >> j) & 0x01) {// if the bit in j position is set then we have the key for this channel
k = j;
break;
}
}
// map the key value to a pulseaudio channel position
switch (k) {
case 0: channel_map->pos[i] = SND_CHMAP_FL; break;
case 1: channel_map->pos[i] = SND_CHMAP_FR; break;
case 2: channel_map->pos[i] = SND_CHMAP_FC; break;
case 3: channel_map->pos[i] = SND_CHMAP_LFE; break;
case 4: channel_map->pos[i] = SND_CHMAP_RL; break;
case 5: channel_map->pos[i] = SND_CHMAP_RR; break;
case 6: channel_map->pos[i] = SND_CHMAP_FLC; break;
case 7: channel_map->pos[i] = SND_CHMAP_FRC; break;
case 8: channel_map->pos[i] = SND_CHMAP_RC; break;
case 9: channel_map->pos[i] = SND_CHMAP_SL; break;
case 10: channel_map->pos[i] = SND_CHMAP_SR; break;
default:
// center is a safe default, at least it's balanced. This shouldn't happen, but it's better to have a fallback
if (verbosity > 0) {
printf("Channel %i coult not be mapped. Falling back to 'center'.\n", i);
}
channel_map->pos[i] = SND_CHMAP_FC;
}
if (verbosity > 0) {
const char *channel_name;
switch (k) {
case 0: channel_name = "Front Left"; break;
case 1: channel_name = "Front Right"; break;
case 2: channel_name = "Front Center"; break;
case 3: channel_name = "LFE / Subwoofer"; break;
case 4: channel_name = "Rear Left"; break;
case 5: channel_name = "Rear Right"; break;
case 6: channel_name = "Front-Left Center"; break;
case 7: channel_name = "Front-Right Center"; break;
case 8: channel_name = "Rear Center"; break;
case 9: channel_name = "Side Left"; break;
case 10: channel_name = "Side Right"; break;
default:
channel_name = "Unknown. Setted to Center.";
}
printf("Channel %i mapped to %s\n", i, channel_name);
}
}
}

if (rate) {
close_alsa(snd);
if (setup_alsa(&snd, format, rate, verbosity, target_latency_ms, output_device) == -1) {
if (setup_alsa(&snd, format, rate, verbosity, target_latency_ms, output_device, cur_channels, &channel_map) == -1) {
if (verbosity > 0)
printf("Unable to set up ALSA with sample rate %u and sample size %hhu, not playing until next format switch.\n", rate, cur_server_size);
printf("Unable to set up ALSA with sample rate %u, sample size %hhu and %u channels, not playing until next format switch.\n", rate, cur_server_size, cur_channels);
snd = NULL;
rate = 0;
}
else {
if (verbosity > 0)
printf("Switched format to sample rate %u and sample size %hhu.\n", rate, cur_server_size);
printf("Switched format to sample rate %u, sample size %hhu and %u channels.\n", rate, cur_server_size, cur_channels);
}
}
}
if (!rate) continue;

samples = (n - 2) / (bytes_per_sample * CHANNELS);
write_frames(snd, &buf[2], samples, bytes_per_sample);
samples = (n - HEADER_SIZE) / (bytes_per_sample * cur_channels);
write_frames(snd, &buf[HEADER_SIZE], samples, bytes_per_sample, cur_channels);
}
}
2 changes: 1 addition & 1 deletion Receivers/dotnet-windows/ScreamReader/ScreamReader/App.config
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2"/>
</startup>
</configuration>
28 changes: 14 additions & 14 deletions Receivers/dotnet-windows/ScreamReader/ScreamReader/Properties/Resources.Designer.cs
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8 changes: 4 additions & 4 deletions Receivers/dotnet-windows/ScreamReader/ScreamReader/Properties/Settings.Designer.cs
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10 changes: 6 additions & 4 deletions Receivers/dotnet-windows/ScreamReader/ScreamReader/ScreamReader.csproj
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Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@
<OutputType>WinExe</OutputType>
<RootNamespace>ScreamReader</RootNamespace>
<AssemblyName>ScreamReader</AssemblyName>
<TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
<TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
<FileAlignment>512</FileAlignment>
<AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
<TargetFrameworkProfile />
Expand Down Expand Up @@ -38,8 +38,8 @@
<StartupObject />
</PropertyGroup>
<ItemGroup>
<Reference Include="NAudio, Version=1.8.3.0, Culture=neutral, processorArchitecture=MSIL">
<HintPath>..\packages\NAudio.1.8.3\lib\net35\NAudio.dll</HintPath>
<Reference Include="NAudio, Version=1.8.5.0, Culture=neutral, processorArchitecture=MSIL">
<HintPath>..\packages\NAudio.1.8.5\lib\net35\NAudio.dll</HintPath>
</Reference>
<Reference Include="System" />
<Reference Include="System.Core" />
Expand Down Expand Up @@ -97,7 +97,9 @@
</Compile>
</ItemGroup>
<ItemGroup>
<None Include="App.config" />
<None Include="App.config">
<SubType>Designer</SubType>
</None>
</ItemGroup>
<ItemGroup>
<None Include="Resources\if_speaker_volume_103855.png" />
Expand Down

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