diff --git a/doc/APIchanges b/doc/APIchanges index cdb9b6a458..221fea30c2 100644 --- a/doc/APIchanges +++ b/doc/APIchanges @@ -2,6 +2,9 @@ The last version increases of all libraries were on 2023-02-09 API changes, most recent first: +2024-02-xx - xxxxxxxxxx - lavu 58.38.100 - channel_layout.h + Add av_channel_layout_retype(). + 2024-02-xx - xxxxxxxxxx - lavu 58.37.100 - channel_layout.h Add av_channel_layout_custom_init(). diff --git a/libavutil/channel_layout.c b/libavutil/channel_layout.c index 40e31e9d12..7f51c076dc 100644 --- a/libavutil/channel_layout.c +++ b/libavutil/channel_layout.c @@ -1036,3 +1036,109 @@ uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout, return ret; } + +static int64_t masked_description(AVChannelLayout *channel_layout, int start_channel) +{ + uint64_t mask = 0; + for (int i = start_channel; i < channel_layout->nb_channels; i++) { + enum AVChannel ch = channel_layout->u.map[i].id; + if (ch >= 0 && ch < 63 && mask < (1ULL << ch)) + mask |= (1ULL << ch); + else + return AVERROR(EINVAL); + } + return mask; +} + +static int has_channel_names(AVChannelLayout *channel_layout) +{ + if (channel_layout->order != AV_CHANNEL_ORDER_CUSTOM) + return 0; + for (int i = 0; i < channel_layout->nb_channels; i++) + if (channel_layout->u.map[i].name[0]) + return 1; + return 0; +} + +int av_channel_layout_retype(AVChannelLayout *channel_layout, enum AVChannelOrder order, int flags) +{ + int allow_lossy = !(flags & AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS); + int lossy; + + if (!av_channel_layout_check(channel_layout)) + return AVERROR(EINVAL); + + if (channel_layout->order == order) + return 0; + + switch (order) { + case AV_CHANNEL_ORDER_UNSPEC: { + int nb_channels = channel_layout->nb_channels; + if (channel_layout->order == AV_CHANNEL_ORDER_CUSTOM) { + lossy = 0; + for (int i = 0; i < nb_channels; i++) { + if (channel_layout->u.map[i].id != AV_CHAN_UNKNOWN || channel_layout->u.map[i].name[0]) { + lossy = 1; + break; + } + } + } else { + lossy = 1; + } + if (!lossy || allow_lossy) { + av_channel_layout_uninit(channel_layout); + channel_layout->order = AV_CHANNEL_ORDER_UNSPEC; + channel_layout->nb_channels = nb_channels; + return lossy; + } + return AVERROR(ENOSYS); + } + case AV_CHANNEL_ORDER_NATIVE: + if (channel_layout->order == AV_CHANNEL_ORDER_CUSTOM) { + int64_t mask = masked_description(channel_layout, 0); + if (mask < 0) + return AVERROR(ENOSYS); + lossy = has_channel_names(channel_layout); + if (!lossy || allow_lossy) { + av_channel_layout_uninit(channel_layout); + av_channel_layout_from_mask(channel_layout, mask); + return lossy; + } + } + return AVERROR(ENOSYS); + case AV_CHANNEL_ORDER_CUSTOM: { + AVChannelLayout custom = { 0 }; + int ret = av_channel_layout_custom_init(&custom, channel_layout->nb_channels); + if (ret < 0) + return ret; + if (channel_layout->order != AV_CHANNEL_ORDER_UNSPEC) + for (int i = 0; i < channel_layout->nb_channels; i++) + custom.u.map[i].id = av_channel_layout_channel_from_index(channel_layout, i); + av_channel_layout_uninit(channel_layout); + *channel_layout = custom; + return 0; + } + case AV_CHANNEL_ORDER_AMBISONIC: + if (channel_layout->order == AV_CHANNEL_ORDER_CUSTOM) { + int64_t mask; + int nb_channels = channel_layout->nb_channels; + int order = ambisonic_order(channel_layout); + if (order < 0) + return AVERROR(ENOSYS); + mask = masked_description(channel_layout, (order + 1) * (order + 1)); + if (mask < 0) + return AVERROR(ENOSYS); + lossy = has_channel_names(channel_layout); + if (!lossy || allow_lossy) { + av_channel_layout_uninit(channel_layout); + channel_layout->order = AV_CHANNEL_ORDER_AMBISONIC; + channel_layout->nb_channels = nb_channels; + channel_layout->u.mask = mask; + return lossy; + } + } + return AVERROR(ENOSYS); + default: + return AVERROR(EINVAL); + } +} diff --git a/libavutil/channel_layout.h b/libavutil/channel_layout.h index dcc320cbfe..7ee5333ea8 100644 --- a/libavutil/channel_layout.h +++ b/libavutil/channel_layout.h @@ -821,6 +821,46 @@ int av_channel_layout_check(const AVChannelLayout *channel_layout); */ int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1); +/** + * The conversion must be lossless. + */ +#define AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS (1 << 0) + +/** + * Change the AVChannelOrder of a channel layout. + * + * Change of AVChannelOrder can be either lossless or lossy. In case of a + * lossless conversion all the channel designations and the associated channel + * names (if any) are kept. On a lossy conversion the channel names and channel + * designations might be lost depending on the capabilities of the desired + * AVChannelOrder. Note that some conversions are simply not possible in which + * case this function returns AVERROR(ENOSYS). + * + * The following conversions are supported: + * + * Any -> Custom : Always possible, always lossless. + * Any -> Unspecified: Always possible, lossless if channel designations + * are all unknown and channel names are not used, lossy otherwise. + * Custom -> Ambisonic : Possible if it contains ambisonic channels with + * optional non-diegetic channels in the end. Lossy if the channels have + * custom names, lossless otherwise. + * Custom -> Native : Possible if it contains native channels in native + * order. Lossy if the channels have custom names, lossless otherwise. + * + * On error this function keeps the original channel layout untouched. + * + * @param channel_layout channel layout which will be changed + * @param order the desired channel layout order + * @param flags a combination of AV_CHANNEL_LAYOUT_RETYPE_FLAG_* constants + * @return 0 if the conversion was successful and lossless or if the channel + * layout was already in the desired order + * >0 if the conversion was successful but lossy + * AVERROR(ENOSYS) if the conversion was not possible (or would be + * lossy and AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS was specified) + * AVERROR(EINVAL), AVERROR(ENOMEM) on error + */ +int av_channel_layout_retype(AVChannelLayout *channel_layout, enum AVChannelOrder order, int flags); + /** * @} */ diff --git a/libavutil/version.h b/libavutil/version.h index 3b38f8f5da..cebf4a0acd 100644 --- a/libavutil/version.h +++ b/libavutil/version.h @@ -79,7 +79,7 @@ */ #define LIBAVUTIL_VERSION_MAJOR 58 -#define LIBAVUTIL_VERSION_MINOR 37 +#define LIBAVUTIL_VERSION_MINOR 38 #define LIBAVUTIL_VERSION_MICRO 100 #define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \