4 files changed, 24 insertions, 10 deletions

diff --git a/video/out/opengl/common.c b/video/out/opengl/common.c
index 6287fc488b..7121522f4b 100644
--- a/video/out/opengl/common.c
+++ b/video/out/opengl/common.c
@@ -147,13 +147,22 @@ static const struct gl_functions gl_functions[] = {
         .provides = MPGL_CAP_ROW_LENGTH | MPGL_CAP_1D_TEX,
         .functions = (const struct gl_function[]) {
             DEF_FN(GetTexLevelParameteriv),
-            DEF_FN(MapBuffer),
             DEF_FN(ReadBuffer),
             DEF_FN(TexImage1D),
             DEF_FN(UnmapBuffer),
             {0}
         },
     },
+    // GL 2.1 has this as extension only.
+    {
+        .ver_exclude = 300,
+        .ver_es_exclude = 300,
+        .extension = "GL_ARB_map_buffer_range",
+        .functions = (const struct gl_function[]) {
+            DEF_FN(MapBufferRange),
+            {0}
+        },
+    },
     // GL 3.0+ and ES 3.x core only functions.
     {
         .ver_core = 300,
@@ -162,6 +171,7 @@ static const struct gl_functions gl_functions[] = {
             DEF_FN(BindBufferBase),
             DEF_FN(BlitFramebuffer),
             DEF_FN(GetStringi),
+            DEF_FN(MapBufferRange),
             // for ES 3.0
             DEF_FN(ReadBuffer),
             DEF_FN(UnmapBuffer),
diff --git a/video/out/opengl/common.h b/video/out/opengl/common.h
index c55f1654fc..84c27dfea0 100644
--- a/video/out/opengl/common.h
+++ b/video/out/opengl/common.h
@@ -126,7 +126,8 @@ struct GL {
     void (GLAPIENTRY *DeleteBuffers)(GLsizei, const GLuint *);
     void (GLAPIENTRY *BindBuffer)(GLenum, GLuint);
     void (GLAPIENTRY *BindBufferBase)(GLenum, GLuint, GLuint);
-    GLvoid * (GLAPIENTRY * MapBuffer)(GLenum, GLenum);
+    GLvoid * (GLAPIENTRY *MapBufferRange)(GLenum, GLintptr, GLsizeiptr,
+                                          GLbitfield);
     GLboolean (GLAPIENTRY *UnmapBuffer)(GLenum);
     void (GLAPIENTRY *BufferData)(GLenum, intptr_t, const GLvoid *, GLenum);
     void (GLAPIENTRY *ActiveTexture)(GLenum);
diff --git a/video/out/opengl/osd.c b/video/out/opengl/osd.c
index bf03d34e90..d8059166be 100644
--- a/video/out/opengl/osd.c
+++ b/video/out/opengl/osd.c
@@ -139,18 +139,19 @@ static bool upload_pbo(struct mpgl_osd *ctx, struct mpgl_osd_part *osd,
     GL *gl = ctx->gl;
     bool success = true;
     const struct gl_format *fmt = ctx->fmt_table[imgs->format];
-    int pix_stride = gl_bytes_per_pixel(fmt->format, fmt->type);
+    size_t pix_stride = gl_bytes_per_pixel(fmt->format, fmt->type);
+    size_t buffer_size = pix_stride * osd->h * osd->w;
 
     if (!osd->buffer) {
         gl->GenBuffers(1, &osd->buffer);
         gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, osd->buffer);
-        gl->BufferData(GL_PIXEL_UNPACK_BUFFER, osd->w * osd->h * pix_stride,
-                        NULL, GL_DYNAMIC_COPY);
+        gl->BufferData(GL_PIXEL_UNPACK_BUFFER, buffer_size, NULL, GL_DYNAMIC_COPY);
         gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
     }
 
     gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, osd->buffer);
-    char *data = gl->MapBuffer(GL_PIXEL_UNPACK_BUFFER, GL_WRITE_ONLY);
+    char *data = gl->MapBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, buffer_size,
+                                    GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_BUFFER_BIT);
     if (!data) {
         success = false;
     } else {
diff --git a/video/out/opengl/video.c b/video/out/opengl/video.c
index bebe1373d6..edf7c7d1f6 100644
--- a/video/out/opengl/video.c
+++ b/video/out/opengl/video.c
@@ -2870,15 +2870,17 @@ static bool map_image(struct gl_video *p, struct mp_image *mpi)
     for (int n = 0; n < p->plane_count; n++) {
         struct texplane *plane = &vimg->planes[n];
         mpi->stride[n] = mp_image_plane_w(mpi, n) * p->image_desc.bytes[n];
+        size_t buffer_size = mp_image_plane_h(mpi, n) * mpi->stride[n];
         if (!plane->gl_buffer) {
             gl->GenBuffers(1, &plane->gl_buffer);
             gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, plane->gl_buffer);
-            size_t buffer_size = mp_image_plane_h(mpi, n) * mpi->stride[n];
             gl->BufferData(GL_PIXEL_UNPACK_BUFFER, buffer_size,
                            NULL, GL_DYNAMIC_DRAW);
         }
         gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, plane->gl_buffer);
-        mpi->planes[n] = gl->MapBuffer(GL_PIXEL_UNPACK_BUFFER, GL_WRITE_ONLY);
+        mpi->planes[n] = gl->MapBufferRange(GL_PIXEL_UNPACK_BUFFER, 0,
+                                            buffer_size, GL_MAP_WRITE_BIT |
+                                                GL_MAP_INVALIDATE_BUFFER_BIT);
         gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
         if (!mpi->planes[n]) {
             unmap_image(p, mpi);
@@ -3042,9 +3044,9 @@ static void check_gl_features(struct gl_video *p)
         }
     }
 
-    if (gl->es && p->opts.pbo) {
+    if (!gl->MapBufferRange && p->opts.pbo) {
         p->opts.pbo = 0;
-        MP_WARN(p, "Disabling PBOs (GLES unsupported).\n");
+        MP_WARN(p, "Disabling PBOs (GL2.1/GLES2 unsupported).\n");
     }
 
     p->forced_dumb_mode = p->opts.dumb_mode || !have_fbo || !have_texrg;