On Thu, 20 Jan 2022, James Almer wrote:
From: Anton Khirnov <an...@khirnov.net>
The new API is more extensible and allows for custom layouts.
More accurate information is exported, eg for decoders that do not
set a channel layout, lavc will not make one up for them.
Deprecate the old API working with just uint64_t bitmasks.
Expanded and completed by Vittorio Giovara <vittorio.giov...@gmail.com>
and James Almer <jamr...@gmail.com>.
Signed-off-by: Vittorio Giovara <vittorio.giov...@gmail.com>
Signed-off-by: James Almer <jamr...@gmail.com>
---
Changes since last version:
*Implemented Marton's suggestion for av_channel_layout_index_from_string()
and av_channel_layout_channel_from_string(), to not mix designation and
custom name namespaces.
Thanks.
[...]
+enum AVChannel
+av_channel_layout_channel_from_string(const AVChannelLayout *channel_layout,
+ const char *str)
+{
As far as I see this function equvivalent to
int index = av_channel_layout_index_from_string(channel_layout, str);
if (index < 0)
return AV_CHAN_NONE;
return av_channel_layout_channel_from_index(channel_layout, index);
This would avoid code duplication.
[...]
+int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout,
+ const char *str)
+{
+ char *chname, buf[16];
+ enum AVChannel ch = AV_CHAN_NONE;
+
+ switch (channel_layout->order) {
+ case AV_CHANNEL_ORDER_CUSTOM:
+ chname = strstr(str, "@");
+ if (chname) {
+ char buf[16];
+ chname++;
+ av_strlcpy(buf, str, FFMIN(sizeof(buf), chname - str));
+ if (!*chname)
+ chname = NULL;
+ ch = av_channel_from_string(buf);
If designation is present but invalid we should return error, e.g:
if (ch == AV_CHAN_NONE && *buf)
return AVERROR(EINVAL);
[...]
diff --git a/libavutil/channel_layout.h b/libavutil/channel_layout.h
index d39ae1177a..2efac9046a 100644
--- a/libavutil/channel_layout.h
+++ b/libavutil/channel_layout.h
@@ -23,6 +23,10 @@
#define AVUTIL_CHANNEL_LAYOUT_H
#include <stdint.h>
+#include <stdlib.h>
+
+#include "version.h"
+#include "attributes.h"
/**
* @file
@@ -34,6 +38,71 @@
* @{
*/
+enum AVChannel {
+ ///< Invalid channel index
+ AV_CHAN_NONE = -1,
+ AV_CHAN_FRONT_LEFT,
+ AV_CHAN_FRONT_RIGHT,
+ AV_CHAN_FRONT_CENTER,
+ AV_CHAN_LOW_FREQUENCY,
+ AV_CHAN_BACK_LEFT,
+ AV_CHAN_BACK_RIGHT,
+ AV_CHAN_FRONT_LEFT_OF_CENTER,
+ AV_CHAN_FRONT_RIGHT_OF_CENTER,
+ AV_CHAN_BACK_CENTER,
+ AV_CHAN_SIDE_LEFT,
+ AV_CHAN_SIDE_RIGHT,
+ AV_CHAN_TOP_CENTER,
+ AV_CHAN_TOP_FRONT_LEFT,
+ AV_CHAN_TOP_FRONT_CENTER,
+ AV_CHAN_TOP_FRONT_RIGHT,
+ AV_CHAN_TOP_BACK_LEFT,
+ AV_CHAN_TOP_BACK_CENTER,
+ AV_CHAN_TOP_BACK_RIGHT,
+ /** Stereo downmix. */
+ AV_CHAN_STEREO_LEFT = 29,
+ /** See above. */
+ AV_CHAN_STEREO_RIGHT,
+ AV_CHAN_WIDE_LEFT,
+ AV_CHAN_WIDE_RIGHT,
+ AV_CHAN_SURROUND_DIRECT_LEFT,
+ AV_CHAN_SURROUND_DIRECT_RIGHT,
+ AV_CHAN_LOW_FREQUENCY_2,
+ AV_CHAN_TOP_SIDE_LEFT,
+ AV_CHAN_TOP_SIDE_RIGHT,
+ AV_CHAN_BOTTOM_FRONT_CENTER,
+ AV_CHAN_BOTTOM_FRONT_LEFT,
+ AV_CHAN_BOTTOM_FRONT_RIGHT,
+
+ /** Channel is empty can be safely skipped. */
+ AV_CHAN_UNUSED = 64,
+
+ /** Channel contains data, but its position is unknown. */
+ AV_CHAN_UNKWNOWN = 128,
typo: UNKNOWN
No more comments for me, thanks.
Marton
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