fix conditional compilation

1 files changed, 126 insertions, 0 deletions

diff --git a/src/video/ffmpeg.zig b/src/video/ffmpeg.zig
new file mode 100644
index 0000000..03456d5
--- /dev/null
+++ b/src/video/ffmpeg.zig
@@ -0,0 +1,126 @@
+const std = @import("std");
+const c = @import("../c.zig");
+const gl = @import("../gl.zig");
+const build_config = @import("build_config");
+const dec = @import("decoder.zig");
+
+const check = dec.check;
+
+pub const AVDecoder = struct {
+    decoder: dec.Decoder,
+
+    sws_ctx: *c.SwsContext,
+    codec_par: c.AVCodecParameters,
+    codec_ctx: [*c]c.AVCodecContext,
+
+    raw_frame: [*c]c.AVFrame,
+    rgba_frame: [*c]c.AVFrame,
+
+    pub fn init(allocator: std.mem.Allocator, codec_par: c.AVCodecParameters) dec.Errors!*dec.Decoder {
+        const self = try allocator.create(AVDecoder);
+        errdefer allocator.destroy(self);
+
+        const codec = c.avcodec_find_decoder(codec_par.codec_id) orelse return error.UnsupportedCodec;
+
+        var codec_ctx = c.avcodec_alloc_context3(codec) orelse return error.AVAllocationError;
+        errdefer c.avcodec_free_context(&codec_ctx);
+        var raw_frame = c.av_frame_alloc() orelse return error.AVAllocationError;
+        errdefer c.av_frame_free(&raw_frame);
+        var rgba_frame = c.av_frame_alloc() orelse return error.AVAllocationError;
+        errdefer c.av_frame_free(&rgba_frame);
+
+        try check(c.avcodec_parameters_to_context(codec_ctx, &codec_par));
+        try check(c.avcodec_open2(codec_ctx, codec, null));
+        errdefer check(c.avcodec_close(codec_ctx)) catch unreachable;
+
+        const sws_ctx = c.sws_getContext(
+            codec_par.width,
+            codec_par.height,
+            codec_par.format,
+            codec_par.width,
+            codec_par.height,
+            c.AV_PIX_FMT_RGBA,
+            c.SWS_POINT,
+            null,
+            null,
+            0,
+        ) orelse return error.AVGenericError;
+        errdefer c.sws_freeContext(sws_ctx);
+
+        self.* = .{
+            .decoder = .{
+                .process_packet_fn = processPacket,
+                .init_texture_fn = initTexture,
+                .reset_fn = reset,
+                .deinit_fn = deinit,
+                .num_frames = 0,
+            },
+            .sws_ctx = sws_ctx,
+            .codec_par = codec_par,
+            .codec_ctx = codec_ctx,
+            .raw_frame = raw_frame,
+            .rgba_frame = rgba_frame,
+        };
+        return &self.decoder;
+    }
+
+    pub fn deinit(decoder: *dec.Decoder, allocator: std.mem.Allocator) void {
+        const self: *AVDecoder = @fieldParentPtr("decoder", decoder);
+
+        const raw_ptr: [*c][*c]c.AVFrame = &self.raw_frame;
+        const rgba_ptr: [*c][*c]c.AVFrame = &self.rgba_frame;
+        c.av_frame_free(raw_ptr);
+        c.av_frame_free(rgba_ptr);
+
+        c.sws_freeContext(self.sws_ctx);
+        check(c.avcodec_close(self.codec_ctx)) catch unreachable;
+        c.avcodec_free_context(&self.codec_ctx);
+
+        allocator.destroy(self);
+    }
+
+    pub fn reset(decoder: *dec.Decoder) void {
+        const self: *AVDecoder = @fieldParentPtr("decoder", decoder);
+        c.avcodec_flush_buffers(self.codec_ctx);
+    }
+
+    pub fn initTexture(decoder: *dec.Decoder, texture: *const gl.Texture) void {
+        const self: *AVDecoder = @fieldParentPtr("decoder", decoder);
+
+        texture.allocate(
+            self.codec_par.width,
+            self.codec_par.height,
+            self.decoder.num_frames,
+            c.GL_COMPRESSED_RGBA_S3TC_DXT1_EXT,
+        );
+    }
+
+    pub fn processPacket(decoder: *dec.Decoder, packet: *c.AVPacket, texture: ?*const gl.Texture) dec.Errors!bool {
+        const self: *AVDecoder = @fieldParentPtr("decoder", decoder);
+
+        try check(c.avcodec_send_packet(self.codec_ctx, packet));
+        while (true) {
+            const ires = c.avcodec_receive_frame(self.codec_ctx, self.raw_frame);
+            if (ires == c.AVERROR_EOF) return false;
+            if (ires == c.AVERROR(c.EAGAIN)) return true;
+            try check(ires);
+            try check(c.sws_scale_frame(self.sws_ctx, self.rgba_frame, self.raw_frame));
+
+            c.glPixelStorei(c.GL_UNPACK_ROW_LENGTH, @divFloor(self.rgba_frame.*.linesize[0], @sizeOf(u8) * 4));
+
+            if (texture) |tex| {
+                tex.setLayer(
+                    self.rgba_frame.*.width,
+                    self.rgba_frame.*.height,
+                    self.decoder.num_frames,
+                    c.GL_RGBA,
+                    self.rgba_frame.*.data[0],
+                );
+
+                if (tex.type == .TEXTURE_2D) return false;
+            }
+
+            self.decoder.num_frames += 1;
+        }
+    }
+};