diff options
Diffstat (limited to 'libavutil/channel_layout.h')
| -rw-r--r-- | libavutil/channel_layout.h | 51 |
1 files changed, 45 insertions, 6 deletions
diff --git a/libavutil/channel_layout.h b/libavutil/channel_layout.h index 6a1f83005a..bc6befd8e3 100644 --- a/libavutil/channel_layout.h +++ b/libavutil/channel_layout.h @@ -2,20 +2,20 @@ * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> * Copyright (c) 2008 Peter Ross * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * - * Libav is distributed in the hope that it will be useful, + * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public - * License along with Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -36,6 +36,14 @@ /** * @defgroup channel_masks Audio channel masks + * + * A channel layout is a 64-bits integer with a bit set for every channel. + * The number of bits set must be equal to the number of channels. + * The value 0 means that the channel layout is not known. + * @note this data structure is not powerful enough to handle channels + * combinations that have the same channel multiple times, such as + * dual-mono. + * * @{ */ #define AV_CH_FRONT_LEFT 0x00000001 @@ -132,7 +140,12 @@ enum AVMatrixEncoding { * - a channel layout mask, in hexadecimal starting with "0x" (see the * AV_CH_* macros). * - * Example: "stereo+FC" = "2+FC" = "2c+1c" = "0x7" + * @warning Starting from the next major bump the trailing character + * 'c' to specify a number of channels will be required, while a + * channel layout mask could also be specified as a decimal number + * (if and only if not followed by "c"). + * + * Example: "stereo+FC" = "2c+FC" = "2c+1c" = "0x7" */ uint64_t av_get_channel_layout(const char *name); @@ -145,6 +158,12 @@ uint64_t av_get_channel_layout(const char *name); */ void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout); +struct AVBPrint; +/** + * Append a description of a channel layout to a bprint buffer. + */ +void av_bprint_channel_layout(struct AVBPrint *bp, int nb_channels, uint64_t channel_layout); + /** * Return the number of channels in the channel layout. */ @@ -153,7 +172,7 @@ int av_get_channel_layout_nb_channels(uint64_t channel_layout); /** * Return default channel layout for a given number of channels. */ -uint64_t av_get_default_channel_layout(int nb_channels); +int64_t av_get_default_channel_layout(int nb_channels); /** * Get the index of a channel in channel_layout. @@ -180,6 +199,26 @@ uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index); const char *av_get_channel_name(uint64_t channel); /** + * Get the description of a given channel. + * + * @param channel a channel layout with a single channel + * @return channel description on success, NULL on error + */ +const char *av_get_channel_description(uint64_t channel); + +/** + * Get the value and name of a standard channel layout. + * + * @param[in] index index in an internal list, starting at 0 + * @param[out] layout channel layout mask + * @param[out] name name of the layout + * @return 0 if the layout exists, + * <0 if index is beyond the limits + */ +int av_get_standard_channel_layout(unsigned index, uint64_t *layout, + const char **name); + +/** * @} */ |