vo_tct: introduce modern caca alternative

DOCS/man/vo.rst

@@ -387,6 +387,21 @@ Available video output drivers are:
 
     .. note:: This driver is a joke.
 
+``tct``
+    Color Unicode art video output driver that works on a text console.
+    Depends on support of true color by modern terminals to display the images
+    at full color range.
+
+    ``--vo-tct-algo=<algo>``
+        Select how to write the pixels to the terminal.
+
+        half-blocks
+            Uses unicode LOWER HALF BLOCK character to achieve higher vertical
+            resolution. (Default.)
+        plain
+            Uses spaces. Causes vertical resolution to drop twofolds, but in
+            theory works in more places.
+
 ``image``
     Output each frame into an image file in the current directory. Each file
     takes the frame number padded with leading zeros as name.

video/out/vo.c

@@ -59,6 +59,7 @@ extern const struct vo_driver video_out_sdl;
 extern const struct vo_driver video_out_vaapi;
 extern const struct vo_driver video_out_wayland;
 extern const struct vo_driver video_out_rpi;
+extern const struct vo_driver video_out_tct;
 
 const struct vo_driver *const video_out_drivers[] =
 {
@@ -89,6 +90,7 @@ const struct vo_driver *const video_out_drivers[] =
     &video_out_null,
     // should not be auto-selected
     &video_out_image,
+    &video_out_tct,
 #if HAVE_CACA
     &video_out_caca,
 #endif

video/out/vo_tct.c

@@ -0,0 +1,234 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv 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.
+ *
+ * mpv 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 mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <libswscale/swscale.h>
+
+#include "options/m_config.h"
+#include "config.h"
+#include "vo.h"
+#include "sub/osd.h"
+#include "video/sws_utils.h"
+#include "video/mp_image.h"
+
+#define IMGFMT IMGFMT_BGR24
+
+#define ALGO_PLAIN 1
+#define ALGO_HALF_BLOCKS 2
+#define ESC_HIDE_CURSOR "\e[?25l"
+#define ESC_RESTORE_CURSOR "\e[?25h"
+#define ESC_CLEAR_SCREEN "\e[2J"
+#define ESC_CLEAR_COLORS "\e[0m"
+#define ESC_GOTOXY "\e[%d;%df"
+#define ESC_COLOR_BACKGROUND "\e[48;2;%d;%d;%dm"
+#define ESC_COLOR_FOREGROUND "\e[38;2;%d;%d;%dm"
+
+struct vo_tct_opts {
+    int algo;
+};
+
+#define OPT_BASE_STRUCT struct vo_tct_opts
+static const struct m_sub_options vo_tct_conf = {
+    .opts = (const m_option_t[]) {
+        OPT_CHOICE("vo-tct-algo", algo, 0,
+                   ({"plain", ALGO_PLAIN},
+                    {"half-blocks", ALGO_HALF_BLOCKS})),
+        {0}
+    },
+    .defaults = &(const struct vo_tct_opts) {
+        .algo = ALGO_HALF_BLOCKS,
+    },
+    .size = sizeof(struct vo_tct_opts),
+};
+
+struct priv {
+    struct vo_tct_opts *opts;
+    size_t buffer_size;
+    char *buffer;
+    int swidth;
+    int sheight;
+    struct mp_image *frame;
+    struct mp_rect src;
+    struct mp_rect dst;
+    struct mp_sws_context *sws;
+};
+
+static void write_plain(
+    const int dwidth, const int dheight,
+    const int swidth, const int sheight,
+    const unsigned char *source, const int source_stride)
+{
+    assert(source);
+    const int tx = (dwidth - swidth) / 2;
+    const int ty = (dheight - sheight) / 2;
+    for (int y = 0; y < sheight; y++) {
+        const unsigned char *row = source + y * source_stride;
+        printf(ESC_GOTOXY, ty + y, tx);
+        for (int x = 0; x < swidth; x++) {
+            unsigned char b = *row++;
+            unsigned char g = *row++;
+            unsigned char r = *row++;
+            printf(ESC_COLOR_BACKGROUND, r, g, b);
+            printf(" ");
+        }
+        printf(ESC_CLEAR_COLORS);
+    }
+    printf("\n");
+}
+
+static void write_half_blocks(
+    const int dwidth, const int dheight,
+    const int swidth, const int sheight,
+    unsigned char *source, int source_stride)
+{
+    assert(source);
+    const int tx = (dwidth - swidth) / 2;
+    const int ty = (dheight - sheight) / 2;
+    for (int y = 0; y < sheight * 2; y += 2) {
+        const unsigned char *row_up = source + y * source_stride;
+        const unsigned char *row_down = source + (y + 1) * source_stride;
+        printf(ESC_GOTOXY, ty + y / 2, tx);
+        for (int x = 0; x < swidth; x++) {
+            unsigned char b_up = *row_up++;
+            unsigned char g_up = *row_up++;
+            unsigned char r_up = *row_up++;
+            unsigned char b_down = *row_down++;
+            unsigned char g_down = *row_down++;
+            unsigned char r_down = *row_down++;
+            printf(ESC_COLOR_BACKGROUND, r_up, g_up, b_up);
+            printf(ESC_COLOR_FOREGROUND, r_down, g_down, b_down);
+            printf("▄");
+        }
+        printf(ESC_CLEAR_COLORS);
+    }
+    printf("\n");
+}
+
+static int reconfig(struct vo *vo, struct mp_image_params *params)
+{
+    struct priv *p = vo->priv;
+
+    struct winsize winsize;
+    ioctl(STDOUT_FILENO, TIOCGWINSZ, &winsize);
+    vo->dwidth = winsize.ws_col;
+    vo->dheight = winsize.ws_row;
+
+    struct mp_osd_res osd;
+    vo_get_src_dst_rects(vo, &p->src, &p->dst, &osd);
+    p->swidth = p->dst.x1 - p->dst.x0;
+    p->sheight = p->dst.y1 - p->dst.y0;
+
+    if (p->buffer)
+        free(p->buffer);
+
+    mp_sws_set_from_cmdline(p->sws, vo->opts->sws_opts);
+    p->sws->src = *params;
+    p->sws->dst = (struct mp_image_params) {
+        .imgfmt = IMGFMT,
+        .w = p->swidth,
+        .h = p->sheight,
+        .p_w = 1,
+        .p_h = 1,
+    };
+
+    const int mul = (p->opts->algo == ALGO_PLAIN ? 1 : 2);
+    p->frame = mp_image_alloc(IMGFMT, p->swidth, p->sheight * mul);
+    if (!p->frame)
+        return -1;
+
+    if (mp_sws_reinit(p->sws) < 0)
+        return -1;
+
+    printf(ESC_HIDE_CURSOR);
+    printf(ESC_CLEAR_SCREEN);
+    vo->want_redraw = true;
+    return 0;
+}
+
+static void draw_image(struct vo *vo, mp_image_t *mpi)
+{
+    struct priv *p = vo->priv;
+    struct mp_image src = *mpi;
+    // XXX: pan, crop etc.
+    mp_sws_scale(p->sws, p->frame, &src);
+    talloc_free(mpi);
+}
+
+static void flip_page(struct vo *vo)
+{
+    struct priv *p = vo->priv;
+    if (p->opts->algo == ALGO_PLAIN) {
+        write_plain(
+            vo->dwidth, vo->dheight, p->swidth, p->sheight,
+            p->frame->planes[0], p->frame->stride[0]);
+    } else {
+        write_half_blocks(
+            vo->dwidth, vo->dheight, p->swidth, p->sheight,
+            p->frame->planes[0], p->frame->stride[0]);
+    }
+    fflush(stdout);
+}
+
+static void uninit(struct vo *vo)
+{
+    printf(ESC_RESTORE_CURSOR);
+    printf(ESC_CLEAR_SCREEN);
+    printf(ESC_GOTOXY, 0, 0);
+    struct priv *p = vo->priv;
+    if (p->buffer)
+        talloc_free(p->buffer);
+    if (p->sws)
+        talloc_free(p->sws);
+}
+
+static int preinit(struct vo *vo)
+{
+    // most terminal characters aren't 1:1, so we default to 2:1.
+    // if user passes their own value of choice, it'll be scaled accordingly.
+    vo->monitor_par = vo->opts->monitor_pixel_aspect * 2;
+
+    struct priv *p = vo->priv;
+    p->opts = mp_get_config_group(vo, vo->global, &vo_tct_conf);
+    p->sws = mp_sws_alloc(vo);
+    return 0;
+}
+
+static int query_format(struct vo *vo, int format)
+{
+    return format == IMGFMT;
+}
+
+static int control(struct vo *vo, uint32_t request, void *data)
+{
+    return VO_NOTIMPL;
+}
+
+const struct vo_driver video_out_tct = {
+    .name = "tct",
+    .description = "true-color terminals",
+    .preinit = preinit,
+    .query_format = query_format,
+    .reconfig = reconfig,
+    .control = control,
+    .draw_image = draw_image,
+    .flip_page = flip_page,
+    .uninit = uninit,
+    .priv_size = sizeof(struct priv),
+    .global_opts = &vo_tct_conf,
+};

wscript_build.py

@@ -375,6 +375,7 @@ def build(ctx):
         ( "video/out/vo_opengl.c",               "gl" ),
         ( "video/out/vo_opengl_cb.c",            "gl" ),
         ( "video/out/vo_sdl.c",                  "sdl2" ),
+        ( "video/out/vo_tct.c",                  "posix" ),
         ( "video/out/vo_vaapi.c",                "vaapi-x11" ),
         ( "video/out/vo_vdpau.c",                "vdpau" ),
         ( "video/out/vo_wayland.c",              "wayland" ),