diff options
author | Steven Robertson <steven@strobe.cc> | 2012-07-11 09:14:57 +0400 |
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committer | Stefano Sabatini <stefasab@gmail.com> | 2012-07-22 14:17:34 +0400 |
commit | 82ecae8a7069104698d491000b37629cd8d96fd8 (patch) | |
tree | 90de57d08d4e0c14ff9b05f40172b25255a30392 /libavfilter/vf_alphamerge.c | |
parent | 8c2ce16f93be0fc1362ab74846b46c9818da14be (diff) |
lavfi: add alphaextract and alphamerge filters
These filters are designed for storing and transmitting video sequences
with alpha using higher-efficiency codecs such as x264 which don't
natively support an alpha channel. 'alphaextract' takes an input stream
with an alpha channel and returns a video containing just the alpha
component as a grayscale value; 'alphamerge' takes an RGB or YUV stream
and adds an alpha channel recovered from a second grayscale stream.
Signed-off-by: Steven Robertson <steven@strobe.cc>
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
Diffstat (limited to 'libavfilter/vf_alphamerge.c')
-rw-r--r-- | libavfilter/vf_alphamerge.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/libavfilter/vf_alphamerge.c b/libavfilter/vf_alphamerge.c new file mode 100644 index 0000000000..67422a1df1 --- /dev/null +++ b/libavfilter/vf_alphamerge.c @@ -0,0 +1,212 @@ +/* + * Copyright (c) 2012 Steven Robertson + * + * This file is part of FFmpeg. + * + * 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. + * + * 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 FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * copy an alpha component from another video's luma + */ + +#include <string.h> + +#include "libavutil/pixfmt.h" +#include "avfilter.h" +#include "bufferqueue.h" +#include "drawutils.h" +#include "formats.h" +#include "internal.h" +#include "video.h" + +enum { Y, U, V, A }; + +typedef struct { + int frame_requested; + int is_packed_rgb; + uint8_t rgba_map[4]; + struct FFBufQueue queue_main; + struct FFBufQueue queue_alpha; +} AlphaMergeContext; + +static av_cold void uninit(AVFilterContext *ctx) +{ + AlphaMergeContext *merge = ctx->priv; + ff_bufqueue_discard_all(&merge->queue_main); + ff_bufqueue_discard_all(&merge->queue_alpha); +} + +static int query_formats(AVFilterContext *ctx) +{ + enum PixelFormat main_fmts[] = { + PIX_FMT_YUVA444P, PIX_FMT_YUVA422P, PIX_FMT_YUVA420P, + PIX_FMT_RGBA, PIX_FMT_BGRA, PIX_FMT_ARGB, PIX_FMT_ABGR, + PIX_FMT_NONE + }; + enum PixelFormat alpha_fmts[] = { PIX_FMT_GRAY8, PIX_FMT_NONE }; + AVFilterFormats *main_formats = ff_make_format_list(main_fmts); + AVFilterFormats *alpha_formats = ff_make_format_list(alpha_fmts); + ff_formats_ref(main_formats, &ctx->inputs[0]->out_formats); + ff_formats_ref(alpha_formats, &ctx->inputs[1]->out_formats); + ff_formats_ref(main_formats, &ctx->outputs[0]->in_formats); + return 0; +} + +static int config_input_main(AVFilterLink *inlink) +{ + AlphaMergeContext *merge = inlink->dst->priv; + merge->is_packed_rgb = + ff_fill_rgba_map(merge->rgba_map, inlink->format) >= 0; + return 0; +} + +static int config_output(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + AVFilterLink *mainlink = ctx->inputs[0]; + AVFilterLink *alphalink = ctx->inputs[1]; + if (mainlink->w != alphalink->w || mainlink->h != alphalink->h) { + av_log(ctx, AV_LOG_ERROR, + "Input frame sizes do not match (%dx%d vs %dx%d).\n", + mainlink->w, mainlink->h, + alphalink->w, alphalink->h); + return AVERROR(EINVAL); + } + + outlink->w = mainlink->w; + outlink->h = mainlink->h; + outlink->time_base = mainlink->time_base; + outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio; + outlink->frame_rate = mainlink->frame_rate; + return 0; +} + +static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref) {} +static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) {} + +static void draw_frame(AVFilterContext *ctx, + AVFilterBufferRef *main_buf, + AVFilterBufferRef *alpha_buf) +{ + AlphaMergeContext *merge = ctx->priv; + int h = main_buf->video->h; + + if (merge->is_packed_rgb) { + int x, y; + uint8_t *pin, *pout; + for (y = 0; y < h; y++) { + pin = alpha_buf->data[0] + y * alpha_buf->linesize[0]; + pout = main_buf->data[0] + y * main_buf->linesize[0] + merge->rgba_map[A]; + for (x = 0; x < main_buf->video->w; x++) { + *pout = *pin; + pin += 1; + pout += 4; + } + } + } else { + int y; + const int main_linesize = main_buf->linesize[A]; + const int alpha_linesize = alpha_buf->linesize[Y]; + for (y = 0; y < h && y < alpha_buf->video->h; y++) { + memcpy(main_buf->data[A] + y * main_linesize, + alpha_buf->data[Y] + y * alpha_linesize, + FFMIN(main_linesize, alpha_linesize)); + } + } + ff_draw_slice(ctx->outputs[0], 0, h, 1); +} + +static void end_frame(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + AlphaMergeContext *merge = ctx->priv; + + int is_alpha = (inlink == ctx->inputs[1]); + struct FFBufQueue *queue = + (is_alpha ? &merge->queue_alpha : &merge->queue_main); + ff_bufqueue_add(ctx, queue, inlink->cur_buf); + inlink->cur_buf = NULL; + + while (1) { + AVFilterBufferRef *main_buf, *alpha_buf; + + if (!ff_bufqueue_peek(&merge->queue_main, 0) || + !ff_bufqueue_peek(&merge->queue_alpha, 0)) break; + + main_buf = ff_bufqueue_get(&merge->queue_main); + alpha_buf = ff_bufqueue_get(&merge->queue_alpha); + + ctx->outputs[0]->out_buf = main_buf; + ff_start_frame(ctx->outputs[0], avfilter_ref_buffer(main_buf, ~0)); + merge->frame_requested = 0; + draw_frame(ctx, main_buf, alpha_buf); + ff_end_frame(ctx->outputs[0]); + avfilter_unref_buffer(alpha_buf); + } +} + +static int request_frame(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + AlphaMergeContext *merge = ctx->priv; + int in, ret; + + merge->frame_requested = 1; + while (merge->frame_requested) { + in = ff_bufqueue_peek(&merge->queue_main, 0) ? 0 : 1; + ret = ff_request_frame(ctx->inputs[in]); + if (ret < 0) + return ret; + } + return 0; +} + +AVFilter avfilter_vf_alphamerge = { + .name = "alphamerge", + .description = NULL_IF_CONFIG_SMALL("Copy the luma value of the second " + "input into the alpha channel of the first input."), + .uninit = uninit, + .priv_size = sizeof(AlphaMergeContext), + .query_formats = query_formats, + + .inputs = (const AVFilterPad[]) { + { .name = "main", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = config_input_main, + .get_video_buffer = ff_null_get_video_buffer, + .start_frame = start_frame, + .draw_slice = draw_slice, + .end_frame = end_frame, + .min_perms = AV_PERM_READ | AV_PERM_WRITE, + .rej_perms = AV_PERM_REUSE2 | AV_PERM_PRESERVE }, + { .name = "alpha", + .type = AVMEDIA_TYPE_VIDEO, + .start_frame = start_frame, + .draw_slice = draw_slice, + .end_frame = end_frame, + .min_perms = AV_PERM_READ, + .rej_perms = AV_PERM_REUSE2 }, + { .name = NULL } + }, + .outputs = (const AVFilterPad[]) { + { .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = config_output, + .request_frame = request_frame }, + { .name = NULL } + }, +}; |