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transcoding: moved determination of audio encoder settings to externa… 
…l functions
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@stbenz @perexg
stbenz authored and perexg committed Jun 8, 2015
1 parent 688c42f commit cdbb459
Showing 1 changed file with 152 additions and 135 deletions.
287 changes: 152 additions & 135 deletions src/plumbing/transcoding.c
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Expand Up @@ -182,6 +182,128 @@ transcode_opt_set_int(transcoder_t *t, transcoder_stream_t *ts,
return 0;
}

/**
* get best effort sample rate
*/
static int
transcode_get_sample_rate(int rate, AVCodec *codec)
{
/* if codec only supports certain rates, check if rate is available */
if (codec->supported_samplerates) {
/* Find if we have a matching sample_rate */
int acount = 0;
int rate_alt = 0;
while (codec->supported_samplerates[acount] > 0) {
if (codec->supported_samplerates[acount] == rate) {
/* original rate supported by codec */
return rate;
}

/* check for highest available rate smaller that the original rate */
if (codec->supported_samplerates[acount] > rate_alt &&
codec->supported_samplerates[acount] < rate) {
rate_alt = codec->supported_samplerates[acount];
}
acount++;
}

return rate_alt;
}


return rate;
}

/**
* get best effort sample format
*/
static enum AVSampleFormat
transcode_get_sample_fmt(enum AVSampleFormat fmt, AVCodec *codec)
{
/* if codec only supports certain formats, check if selected format is available */
if (codec->sample_fmts) {
/* Find if we have a matching sample_fmt */
int acount = 0;
while (codec->sample_fmts[acount] > AV_SAMPLE_FMT_NONE) {
if (codec->sample_fmts[acount] == fmt) {
/* original format supported by codec */
return fmt;
}
acount++;
}

/* use first supported sample format */
if (acount > 0) {
return codec->sample_fmts[0];
} else {
return AV_SAMPLE_FMT_NONE;
}
}

return fmt;
}

/**
* get best effort channel layout
*/
static uint64_t
transcode_get_channel_layout(int *channels, AVCodec *codec)
{
uint64_t channel_layout = AV_CH_LAYOUT_STEREO;

/* use channel layout based on input field */
switch (*channels) {
case 1: channel_layout = AV_CH_LAYOUT_MONO; break;
case 2: channel_layout = AV_CH_LAYOUT_STEREO; break;
case 3: channel_layout = AV_CH_LAYOUT_SURROUND; break;
case 4: channel_layout = AV_CH_LAYOUT_QUAD; break;
case 5: channel_layout = AV_CH_LAYOUT_5POINT0; break;
case 6: channel_layout = AV_CH_LAYOUT_5POINT1; break;
case 7: channel_layout = AV_CH_LAYOUT_6POINT1; break;
case 8: channel_layout = AV_CH_LAYOUT_7POINT1; break;
}

/* if codec only supports certain layouts, check if selected layout is available */
if (codec->channel_layouts) {
int acount = 0;
uint64_t channel_layout_def = av_get_default_channel_layout(*channels);
uint64_t channel_layout_alt = 0;

while (codec->channel_layouts[acount] > 0) {
if (codec->channel_layouts[acount] == channel_layout) {
/* original layout supported by codec */
return channel_layout;
}

/* check for best matching layout with same or less number of channels */
if (av_get_channel_layout_nb_channels(codec->channel_layouts[acount]) <= *channels) {
if (av_get_channel_layout_nb_channels(codec->channel_layouts[acount]) >
av_get_channel_layout_nb_channels(channel_layout_alt)) {
/* prefer layout with more channels */
channel_layout_alt = codec->channel_layouts[acount];
} else if (av_get_channel_layout_nb_channels(codec->channel_layouts[acount]) ==
av_get_channel_layout_nb_channels(channel_layout_alt) &&
codec->channel_layouts[acount] == channel_layout_def) {
/* prefer default layout for number of channels over alternative layout */
channel_layout_alt = channel_layout_def;
}
}

acount++;
}

if (channel_layout_alt) {
channel_layout = channel_layout_alt;
*channels = av_get_channel_layout_nb_channels(channel_layout_alt);
} else {
channel_layout = 0;
*channels = 0;
}
}

return channel_layout;
}

/**
*
*/
Expand Down Expand Up @@ -421,146 +543,41 @@ transcoder_stream_audio(transcoder_t *t, transcoder_stream_t *ts, th_pkt_t *pkt)

if (octx->codec_id == AV_CODEC_ID_NONE) {
as->aud_enc_pts = pkt->pkt_pts;
octx->sample_rate = ictx->sample_rate;
octx->sample_fmt = ictx->sample_fmt;

if (ocodec->supported_samplerates) {
/* Find if we have a matching sample_rate */
int acount = 0;
octx->sample_rate = 0;
int sample_rate_alt = 0;
while ((octx->sample_rate == 0) && (ocodec->supported_samplerates[acount] > 0)) {
if (ocodec->supported_samplerates[acount] == ictx->sample_rate) {
octx->sample_rate = ictx->sample_rate;
break;
}
if (ocodec->supported_samplerates[acount] > sample_rate_alt &&
ocodec->supported_samplerates[acount] < ictx->sample_rate) {
sample_rate_alt = ocodec->supported_samplerates[acount];
}
acount++;
}
if (octx->sample_rate == 0) {
if (sample_rate_alt > 0) {
tvhtrace("transcode", "%04X: sample_rate not supported, using: %d",
shortid(t), sample_rate_alt);
octx->sample_rate = sample_rate_alt;
} else {
tvherror("transcode", "%04X: Encoder no sample_rate!!??", shortid(t));
transcoder_stream_invalidate(ts);
goto cleanup;
}
}
}
octx->sample_rate = transcode_get_sample_rate(ictx->sample_rate, ocodec);
octx->sample_fmt = transcode_get_sample_fmt(ictx->sample_fmt, ocodec);
octx->time_base = ictx->time_base;
octx->channels = as->aud_channels ? MIN(as->aud_channels, ictx->channels) : ictx->channels;
octx->channel_layout = transcode_get_channel_layout(&octx->channels, ocodec);
octx->bit_rate = as->aud_bitrate ? as->aud_bitrate : 0;
octx->flags |= CODEC_FLAG_GLOBAL_HEADER;

if (ocodec->sample_fmts) {
/* Find if we have a matching sample_fmt */
int acount = 0;
octx->sample_fmt = AV_SAMPLE_FMT_NONE;
while ((octx->sample_fmt == AV_SAMPLE_FMT_NONE) && (ocodec->sample_fmts[acount] > AV_SAMPLE_FMT_NONE)) {
if (ocodec->sample_fmts[acount] == ictx->sample_fmt) {
octx->sample_fmt = ictx->sample_fmt;
break;
}
acount++;
}
if (octx->sample_fmt == AV_SAMPLE_FMT_NONE) {
if (acount > 0) {
tvhtrace("transcode", "%04X: sample_fmt not supported, using: %d",
shortid(t), ocodec->sample_fmts[0]);
octx->sample_fmt = ocodec->sample_fmts[0];
} else {
tvherror("transcode", "%04X: Encoder no sample_fmt!!??", shortid(t));
transcoder_stream_invalidate(ts);
goto cleanup;
}
}
if (!octx->sample_rate) {
tvherror("transcode", "%04X: audio encoder has no suitable sample rate!", shortid(t));
transcoder_stream_invalidate(ts);
goto cleanup;
} else {
tvhdebug("transcode", "%04X: using audio sample rate %d",
shortid(t), octx->sample_rate);
}

octx->time_base = ictx->time_base;
octx->channels = as->aud_channels ? MIN(as->aud_channels, ictx->channels) : ictx->channels;
octx->bit_rate = as->aud_bitrate ? as->aud_bitrate : 0;
octx->flags |= CODEC_FLAG_GLOBAL_HEADER;


switch (octx->channels) {
case 1:
octx->channel_layout = AV_CH_LAYOUT_MONO;
break;

case 2:
octx->channel_layout = AV_CH_LAYOUT_STEREO;
break;

case 3:
octx->channel_layout = AV_CH_LAYOUT_SURROUND;
break;

case 4:
octx->channel_layout = AV_CH_LAYOUT_QUAD;
break;

case 5:
octx->channel_layout = AV_CH_LAYOUT_5POINT0;
break;

case 6:
octx->channel_layout = AV_CH_LAYOUT_5POINT1;
break;

case 7:
octx->channel_layout = AV_CH_LAYOUT_6POINT1;
break;

case 8:
octx->channel_layout = AV_CH_LAYOUT_7POINT1;
break;

default:
break;
if (octx->sample_fmt == AV_SAMPLE_FMT_NONE) {
tvherror("transcode", "%04X: audio encoder has no suitable sample format!", shortid(t));
transcoder_stream_invalidate(ts);
goto cleanup;
} else {
tvhdebug("transcode", "%04X: using audio sample format %s",
shortid(t), av_get_sample_fmt_name(octx->sample_fmt));
}

if (ocodec->channel_layouts) {
int acount = 0;
uint64_t channel_layout = octx->channel_layout;
uint64_t channel_layout_def = av_get_default_channel_layout(octx->channels);
uint64_t channel_layout_alt = 0;
int channels_alt = 0;
/* check if requested layout is available and find best suited alternative layout */
octx->channel_layout = 0;
while ((octx->channel_layout == 0) && (ocodec->channel_layouts[acount] > 0)) {
if (ocodec->channel_layouts[acount] == channel_layout) {
octx->channel_layout = channel_layout;
break;
}
if (av_get_channel_layout_nb_channels(ocodec->channel_layouts[acount]) <= octx->channels) {
if (av_get_channel_layout_nb_channels(ocodec->channel_layouts[acount]) > channels_alt) {
channel_layout_alt = ocodec->channel_layouts[acount];
channels_alt = av_get_channel_layout_nb_channels(channel_layout_alt);
} else if (av_get_channel_layout_nb_channels(ocodec->channel_layouts[acount]) == channels_alt &&
channel_layout_alt == channel_layout_def) {
channel_layout_alt = channel_layout_def;
channels_alt = av_get_channel_layout_nb_channels(channel_layout_alt);
}
}
acount++;
}

if (octx->channel_layout == 0) {
if (channel_layout_alt != 0) {
/* find next which has same or less channels than decoder. */
char layout_buf[100];
av_get_channel_layout_string(layout_buf, sizeof (layout_buf), channels_alt, channel_layout_alt);
tvhtrace("transcode", "%04X: channel_layout not available, using: %s",
shortid(t), layout_buf);
octx->channel_layout = channel_layout_alt;
octx->channels = channels_alt;
} else {
tvherror("transcode", "%04X: Encoder no channel_layout!!??", shortid(t));
transcoder_stream_invalidate(ts);
goto cleanup;
}
}
if (!octx->channel_layout) {
tvherror("transcode", "%04X: audio encoder has no suitable channel layout!", shortid(t));
transcoder_stream_invalidate(ts);
goto cleanup;
} else {
char layout_buf[100];
av_get_channel_layout_string(layout_buf, sizeof (layout_buf), octx->channels, octx->channel_layout);
tvhdebug("transcode", "%04X: using audio channel layout %s",
shortid(t), layout_buf);
}

// Set flags and quality settings, if no bitrate was specified.
Expand Down

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