Merge commit '5d273d3efac340ef8de445c955ff44c7abed4e8f'

* commit '5d273d3efac340ef8de445c955ff44c7abed4e8f':
  avconv: VAAPI hwcontext initialisation and hwaccel helper

Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Makefile

@@ -37,6 +37,7 @@ OBJS-ffmpeg-$(CONFIG_VDA)     += ffmpeg_videotoolbox.o
 endif
 OBJS-ffmpeg-$(CONFIG_VIDEOTOOLBOX) += ffmpeg_videotoolbox.o
 OBJS-ffmpeg-$(CONFIG_LIBMFX)  += ffmpeg_qsv.o
+OBJS-ffmpeg-$(CONFIG_VAAPI)   += ffmpeg_vaapi.o
 OBJS-ffserver                 += ffserver_config.o
 
 TESTTOOLS   = audiogen videogen rotozoom tiny_psnr tiny_ssim base64 audiomatch

configure

@@ -2000,6 +2000,7 @@ HAVE_LIST="
     section_data_rel_ro
     texi2html
     threads
+    vaapi_drm
     vaapi_x11
     vdpau_x11
     winrt
@@ -5872,10 +5873,15 @@ enabled vaapi &&
     check_code cc "va/va.h" "vaCreateSurfaces(0, 0, 0, 0, 0, 0, 0, 0)" ||
     disable vaapi
 
-enabled vaapi && enabled xlib &&
+if enabled vaapi ; then
+    enabled xlib &&
     check_lib2 "va/va.h va/va_x11.h" vaGetDisplay -lva -lva-x11 &&
     enable vaapi_x11
 
+    check_lib2 "va/va.h va/va_drm.h" vaGetDisplayDRM -lva -lva-drm &&
+    enable vaapi_drm
+fi
+
 enabled vdpau &&
     check_cpp_condition vdpau/vdpau.h "defined VDP_DECODER_PROFILE_MPEG4_PART2_ASP" ||
     disable vdpau

ffmpeg.c

@@ -4213,6 +4213,8 @@ static int transcode(void)
         }
     }
 
+    av_buffer_unref(&hw_device_ctx);
+
     /* finished ! */
     ret = 0;
 

ffmpeg.h

@@ -65,6 +65,7 @@ enum HWAccelID {
     HWACCEL_VDA,
     HWACCEL_VIDEOTOOLBOX,
     HWACCEL_QSV,
+    HWACCEL_VAAPI,
 };
 
 typedef struct HWAccel {
@@ -126,6 +127,8 @@ typedef struct OptionsContext {
     int        nb_hwaccels;
     SpecifierOpt *hwaccel_devices;
     int        nb_hwaccel_devices;
+    SpecifierOpt *hwaccel_output_formats;
+    int        nb_hwaccel_output_formats;
     SpecifierOpt *autorotate;
     int        nb_autorotate;
 
@@ -325,6 +328,7 @@ typedef struct InputStream {
     /* hwaccel options */
     enum HWAccelID hwaccel_id;
     char  *hwaccel_device;
+    enum AVPixelFormat hwaccel_output_format;
 
     /* hwaccel context */
     enum HWAccelID active_hwaccel_id;
@@ -334,6 +338,7 @@ typedef struct InputStream {
     int  (*hwaccel_retrieve_data)(AVCodecContext *s, AVFrame *frame);
     enum AVPixelFormat hwaccel_pix_fmt;
     enum AVPixelFormat hwaccel_retrieved_pix_fmt;
+    AVBufferRef *hw_frames_ctx;
 
     /* stats */
     // combined size of all the packets read
@@ -544,6 +549,8 @@ extern const AVIOInterruptCB int_cb;
 
 extern const OptionDef options[];
 extern const HWAccel hwaccels[];
+extern int hwaccel_lax_profile_check;
+extern AVBufferRef *hw_device_ctx;
 
 
 void term_init(void);
@@ -576,5 +583,7 @@ int vda_init(AVCodecContext *s);
 int videotoolbox_init(AVCodecContext *s);
 int qsv_init(AVCodecContext *s);
 int qsv_transcode_init(OutputStream *ost);
+int vaapi_decode_init(AVCodecContext *avctx);
+int vaapi_device_init(const char *device);
 
 #endif /* FFMPEG_H */

ffmpeg_filter.c

@@ -24,6 +24,7 @@
 
 #include "libavfilter/avfilter.h"
 #include "libavfilter/buffersink.h"
+#include "libavfilter/buffersrc.h"
 
 #include "libavresample/avresample.h"
 
@@ -38,7 +39,6 @@
 #include "libavutil/imgutils.h"
 #include "libavutil/samplefmt.h"
 
-
 static const enum AVPixelFormat *get_compliance_unofficial_pix_fmts(enum AVCodecID codec_id, const enum AVPixelFormat default_formats[])
 {
     static const enum AVPixelFormat mjpeg_formats[] =
@@ -428,7 +428,7 @@ static int configure_output_video_filter(FilterGraph *fg, OutputFilter *ofilter,
     if (ret < 0)
         return ret;
 
-    if (codec->width || codec->height) {
+    if (!hw_device_ctx && (codec->width || codec->height)) {
         char args[255];
         AVFilterContext *filter;
         AVDictionaryEntry *e = NULL;
@@ -719,6 +719,12 @@ static int configure_input_video_filter(FilterGraph *fg, InputFilter *ifilter,
     char name[255];
     int ret, pad_idx = 0;
     int64_t tsoffset = 0;
+    AVBufferSrcParameters *par = av_buffersrc_parameters_alloc();
+
+    if (!par)
+        return AVERROR(ENOMEM);
+    memset(par, 0, sizeof(*par));
+    par->format = AV_PIX_FMT_NONE;
 
     if (ist->dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
         av_log(NULL, AV_LOG_ERROR, "Cannot connect video filter to audio input\n");
@@ -752,9 +758,15 @@ static int configure_input_video_filter(FilterGraph *fg, InputFilter *ifilter,
     snprintf(name, sizeof(name), "graph %d input from stream %d:%d", fg->index,
              ist->file_index, ist->st->index);
 
+
     if ((ret = avfilter_graph_create_filter(&ifilter->filter, buffer_filt, name,
                                             args.str, NULL, fg->graph)) < 0)
         return ret;
+    par->hw_frames_ctx = ist->hw_frames_ctx;
+    ret = av_buffersrc_parameters_set(ifilter->filter, par);
+    if (ret < 0)
+        return ret;
+    av_freep(&par);
     last_filter = ifilter->filter;
 
     if (ist->autorotate) {
@@ -1010,6 +1022,12 @@ int configure_filtergraph(FilterGraph *fg)
     if ((ret = avfilter_graph_parse2(fg->graph, graph_desc, &inputs, &outputs)) < 0)
         return ret;
 
+    if (hw_device_ctx) {
+        for (i = 0; i < fg->graph->nb_filters; i++) {
+            fg->graph->filters[i]->hw_device_ctx = av_buffer_ref(hw_device_ctx);
+        }
+    }
+
     if (simple && (!inputs || inputs->next || !outputs || outputs->next)) {
         const char *num_inputs;
         const char *num_outputs;

ffmpeg_opt.c

@@ -80,9 +80,14 @@ const HWAccel hwaccels[] = {
 #endif
 #if CONFIG_LIBMFX
     { "qsv",   qsv_init,   HWACCEL_QSV,   AV_PIX_FMT_QSV },
+#endif
+#if CONFIG_VAAPI
+    { "vaapi", vaapi_decode_init, HWACCEL_VAAPI, AV_PIX_FMT_VAAPI },
 #endif
     { 0 },
 };
+int hwaccel_lax_profile_check = 0;
+AVBufferRef *hw_device_ctx;
 
 char *vstats_filename;
 char *sdp_filename;
@@ -441,6 +446,17 @@ static int opt_sdp_file(void *optctx, const char *opt, const char *arg)
     return 0;
 }
 
+#if CONFIG_VAAPI
+static int opt_vaapi_device(void *optctx, const char *opt, const char *arg)
+{
+    int err;
+    err = vaapi_device_init(arg);
+    if (err < 0)
+        exit_program(1);
+    return 0;
+}
+#endif
+
 /**
  * Parse a metadata specifier passed as 'arg' parameter.
  * @param arg  metadata string to parse
@@ -633,6 +649,7 @@ static void add_input_streams(OptionsContext *o, AVFormatContext *ic)
         AVCodecContext *dec = st->codec;
         InputStream *ist = av_mallocz(sizeof(*ist));
         char *framerate = NULL, *hwaccel = NULL, *hwaccel_device = NULL;
+        char *hwaccel_output_format = NULL;
         char *codec_tag = NULL;
         char *next;
         char *discard_str = NULL;
@@ -752,6 +769,19 @@ static void add_input_streams(OptionsContext *o, AVFormatContext *ic)
                 if (!ist->hwaccel_device)
                     exit_program(1);
             }
+
+            MATCH_PER_STREAM_OPT(hwaccel_output_formats, str,
+                                 hwaccel_output_format, ic, st);
+            if (hwaccel_output_format) {
+                ist->hwaccel_output_format = av_get_pix_fmt(hwaccel_output_format);
+                if (ist->hwaccel_output_format == AV_PIX_FMT_NONE) {
+                    av_log(NULL, AV_LOG_FATAL, "Unrecognised hwaccel output "
+                           "format: %s", hwaccel_output_format);
+                }
+            } else {
+                ist->hwaccel_output_format = AV_PIX_FMT_NONE;
+            }
+
             ist->hwaccel_pix_fmt = AV_PIX_FMT_NONE;
 
             break;
@@ -3348,6 +3378,12 @@ const OptionDef options[] = {
     { "hwaccel_device",   OPT_VIDEO | OPT_STRING | HAS_ARG | OPT_EXPERT |
                           OPT_SPEC | OPT_INPUT,                                  { .off = OFFSET(hwaccel_devices) },
         "select a device for HW acceleration", "devicename" },
+    { "hwaccel_output_format", OPT_VIDEO | OPT_STRING | HAS_ARG | OPT_EXPERT |
+                          OPT_SPEC | OPT_INPUT,                                  { .off = OFFSET(hwaccel_output_formats) },
+        "select output format used with HW accelerated decoding", "format" },
+    { "hwaccel_output_format", OPT_VIDEO | OPT_STRING | HAS_ARG | OPT_EXPERT |
+                          OPT_SPEC | OPT_INPUT,                                  { .off = OFFSET(hwaccel_output_formats) },
+        "select output format used with HW accelerated decoding", "format" },
 #if CONFIG_VDA || CONFIG_VIDEOTOOLBOX
     { "videotoolbox_pixfmt", HAS_ARG | OPT_STRING | OPT_EXPERT, { &videotoolbox_pixfmt}, "" },
 #endif
@@ -3356,6 +3392,8 @@ const OptionDef options[] = {
     { "autorotate",       HAS_ARG | OPT_BOOL | OPT_SPEC |
                           OPT_EXPERT | OPT_INPUT,                                { .off = OFFSET(autorotate) },
         "automatically insert correct rotate filters" },
+    { "hwaccel_lax_profile_check", OPT_BOOL | OPT_EXPERT,                        { &hwaccel_lax_profile_check},
+        "attempt to decode anyway if HW accelerated decoder's supported profiles do not exactly match the stream" },
 
     /* audio options */
     { "aframes",        OPT_AUDIO | HAS_ARG  | OPT_PERFILE | OPT_OUTPUT,           { .func_arg = opt_audio_frames },
@@ -3439,5 +3477,10 @@ const OptionDef options[] = {
     { "dn", OPT_BOOL | OPT_VIDEO | OPT_OFFSET | OPT_INPUT | OPT_OUTPUT, { .off = OFFSET(data_disable) },
         "disable data" },
 
+#if CONFIG_VAAPI
+    { "vaapi_device", HAS_ARG | OPT_EXPERT, { .func_arg = opt_vaapi_device },
+        "set VAAPI hardware device (DRM path or X11 display name)", "device" },
+#endif
+
     { NULL, },
 };

ffmpeg_vaapi.c

@@ -0,0 +1,626 @@
+/*
+ * 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
+ */
+
+#include "config.h"
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <va/va.h>
+#if HAVE_VAAPI_X11
+#   include <va/va_x11.h>
+#endif
+#if HAVE_VAAPI_DRM
+#   include <va/va_drm.h>
+#endif
+
+#include "libavutil/avassert.h"
+#include "libavutil/avconfig.h"
+#include "libavutil/buffer.h"
+#include "libavutil/frame.h"
+#include "libavutil/hwcontext.h"
+#include "libavutil/hwcontext_vaapi.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixfmt.h"
+
+#include "libavcodec/vaapi.h"
+
+#include "ffmpeg.h"
+
+
+static AVClass vaapi_class = {
+    .class_name = "vaapi",
+    .item_name  = av_default_item_name,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+#define DEFAULT_SURFACES 20
+
+typedef struct VAAPIDecoderContext {
+    const AVClass *class;
+
+    AVBufferRef       *device_ref;
+    AVHWDeviceContext *device;
+    AVBufferRef       *frames_ref;
+    AVHWFramesContext *frames;
+
+    VAProfile    va_profile;
+    VAEntrypoint va_entrypoint;
+    VAConfigID   va_config;
+    VAContextID  va_context;
+
+    enum AVPixelFormat decode_format;
+    int decode_width;
+    int decode_height;
+    int decode_surfaces;
+
+    // The output need not have the same format, width and height as the
+    // decoded frames - the copy for non-direct-mapped access is actually
+    // a whole vpp instance which can do arbitrary scaling and format
+    // conversion.
+    enum AVPixelFormat output_format;
+
+    struct vaapi_context decoder_vaapi_context;
+} VAAPIDecoderContext;
+
+
+static int vaapi_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
+{
+    InputStream *ist = avctx->opaque;
+    VAAPIDecoderContext *ctx = ist->hwaccel_ctx;
+    int err;
+
+    err = av_hwframe_get_buffer(ctx->frames_ref, frame, 0);
+    if (err < 0) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to allocate decoder surface.\n");
+    } else {
+        av_log(ctx, AV_LOG_DEBUG, "Decoder given surface %#x.\n",
+               (unsigned int)(uintptr_t)frame->data[3]);
+    }
+    return err;
+}
+
+static int vaapi_retrieve_data(AVCodecContext *avctx, AVFrame *input)
+{
+    InputStream *ist = avctx->opaque;
+    VAAPIDecoderContext *ctx = ist->hwaccel_ctx;
+    AVFrame *output = 0;
+    int err;
+
+    av_assert0(input->format == AV_PIX_FMT_VAAPI);
+
+    if (ctx->output_format == AV_PIX_FMT_VAAPI) {
+        // Nothing to do.
+        return 0;
+    }
+
+    av_log(ctx, AV_LOG_DEBUG, "Retrieve data from surface %#x.\n",
+           (unsigned int)(uintptr_t)input->data[3]);
+
+    output = av_frame_alloc();
+    if (!output)
+        return AVERROR(ENOMEM);
+
+    output->format = ctx->output_format;
+
+    err = av_hwframe_transfer_data(output, input, 0);
+    if (err < 0) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to transfer data to "
+               "output frame: %d.\n", err);
+        goto fail;
+    }
+
+    err = av_frame_copy_props(output, input);
+    if (err < 0) {
+        av_frame_unref(output);
+        goto fail;
+    }
+
+    av_frame_unref(input);
+    av_frame_move_ref(input, output);
+    av_frame_free(&output);
+
+    return 0;
+
+fail:
+    if (output)
+        av_frame_free(&output);
+    return err;
+}
+
+
+static const struct {
+    enum AVCodecID codec_id;
+    int codec_profile;
+    VAProfile va_profile;
+} vaapi_profile_map[] = {
+#define MAP(c, p, v) { AV_CODEC_ID_ ## c, FF_PROFILE_ ## p, VAProfile ## v }
+    MAP(MPEG2VIDEO,  MPEG2_SIMPLE,    MPEG2Simple ),
+    MAP(MPEG2VIDEO,  MPEG2_MAIN,      MPEG2Main   ),
+    MAP(H263,        UNKNOWN,         H263Baseline),
+    MAP(MPEG4,       MPEG4_SIMPLE,    MPEG4Simple ),
+    MAP(MPEG4,       MPEG4_ADVANCED_SIMPLE,
+                               MPEG4AdvancedSimple),
+    MAP(MPEG4,       MPEG4_MAIN,      MPEG4Main   ),
+    MAP(H264,        H264_CONSTRAINED_BASELINE,
+                           H264ConstrainedBaseline),
+    MAP(H264,        H264_BASELINE,   H264Baseline),
+    MAP(H264,        H264_MAIN,       H264Main    ),
+    MAP(H264,        H264_HIGH,       H264High    ),
+#if VA_CHECK_VERSION(0, 37, 0)
+    MAP(HEVC,        HEVC_MAIN,       HEVCMain    ),
+#endif
+    MAP(WMV3,        VC1_SIMPLE,      VC1Simple   ),
+    MAP(WMV3,        VC1_MAIN,        VC1Main     ),
+    MAP(WMV3,        VC1_COMPLEX,     VC1Advanced ),
+    MAP(WMV3,        VC1_ADVANCED,    VC1Advanced ),
+    MAP(VC1,         VC1_SIMPLE,      VC1Simple   ),
+    MAP(VC1,         VC1_MAIN,        VC1Main     ),
+    MAP(VC1,         VC1_COMPLEX,     VC1Advanced ),
+    MAP(VC1,         VC1_ADVANCED,    VC1Advanced ),
+#if VA_CHECK_VERSION(0, 35, 0)
+    MAP(VP8,         UNKNOWN,       VP8Version0_3 ),
+#endif
+#if VA_CHECK_VERSION(0, 37, 1)
+    MAP(VP9,         VP9_0,           VP9Profile0 ),
+#endif
+#undef MAP
+};
+
+static int vaapi_build_decoder_config(VAAPIDecoderContext *ctx,
+                                      AVCodecContext *avctx,
+                                      int fallback_allowed)
+{
+    AVVAAPIDeviceContext *hwctx = ctx->device->hwctx;
+    AVVAAPIHWConfig *hwconfig = NULL;
+    AVHWFramesConstraints *constraints = NULL;
+    VAStatus vas;
+    int err, i, j;
+    int loglevel = fallback_allowed ? AV_LOG_VERBOSE : AV_LOG_ERROR;
+    const AVCodecDescriptor *codec_desc;
+    const AVPixFmtDescriptor *pix_desc;
+    enum AVPixelFormat pix_fmt;
+    VAProfile profile, *profile_list = NULL;
+    int profile_count, exact_match, alt_profile;
+
+    codec_desc = avcodec_descriptor_get(avctx->codec_id);
+    if (!codec_desc) {
+        err = AVERROR(EINVAL);
+        goto fail;
+    }
+
+    profile_count = vaMaxNumProfiles(hwctx->display);
+    profile_list = av_malloc(profile_count * sizeof(VAProfile));
+    if (!profile_list) {
+        err = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    vas = vaQueryConfigProfiles(hwctx->display,
+                                profile_list, &profile_count);
+    if (vas != VA_STATUS_SUCCESS) {
+        av_log(ctx, loglevel, "Failed to query profiles: %d (%s).\n",
+               vas, vaErrorStr(vas));
+        err = AVERROR(EIO);
+        goto fail;
+    }
+
+    profile = VAProfileNone;
+    exact_match = 0;
+
+    for (i = 0; i < FF_ARRAY_ELEMS(vaapi_profile_map); i++) {
+        int profile_match = 0;
+        if (avctx->codec_id != vaapi_profile_map[i].codec_id)
+            continue;
+        if (avctx->profile == vaapi_profile_map[i].codec_profile)
+            profile_match = 1;
+        profile = vaapi_profile_map[i].va_profile;
+        for (j = 0; j < profile_count; j++) {
+            if (profile == profile_list[j]) {
+                exact_match = profile_match;
+                break;
+            }
+        }
+        if (j < profile_count) {
+            if (exact_match)
+                break;
+            alt_profile = vaapi_profile_map[i].codec_profile;
+        }
+    }
+    av_free(profile_list);
+
+    if (profile == VAProfileNone) {
+        av_log(ctx, loglevel, "No VAAPI support for codec %s.\n",
+               codec_desc->name);
+        err = AVERROR(ENOSYS);
+        goto fail;
+    }
+    if (!exact_match) {
+        if (fallback_allowed || !hwaccel_lax_profile_check) {
+            av_log(ctx, loglevel, "No VAAPI support for codec %s "
+                   "profile %d.\n", codec_desc->name, avctx->profile);
+            if (!fallback_allowed) {
+                av_log(ctx, AV_LOG_WARNING, "If you want attempt decoding "
+                       "anyway with a possibly-incompatible profile, add "
+                       "the option -hwaccel_lax_profile_check.\n");
+            }
+            err = AVERROR(EINVAL);
+            goto fail;
+        } else {
+            av_log(ctx, AV_LOG_WARNING, "No VAAPI support for codec %s "
+                   "profile %d: trying instead with profile %d.\n",
+                   codec_desc->name, avctx->profile, alt_profile);
+            av_log(ctx, AV_LOG_WARNING, "This may fail or give "
+                   "incorrect results, depending on your hardware.\n");
+        }
+    }
+
+    ctx->va_profile = profile;
+    ctx->va_entrypoint = VAEntrypointVLD;
+
+    vas = vaCreateConfig(hwctx->display, ctx->va_profile,
+                         ctx->va_entrypoint, 0, 0, &ctx->va_config);
+    if (vas != VA_STATUS_SUCCESS) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to create decode pipeline "
+               "configuration: %d (%s).\n", vas, vaErrorStr(vas));
+        err = AVERROR(EIO);
+        goto fail;
+    }
+
+    hwconfig = av_hwdevice_hwconfig_alloc(ctx->device_ref);
+    if (!hwconfig) {
+        err = AVERROR(ENOMEM);
+        goto fail;
+    }
+    hwconfig->config_id = ctx->va_config;
+
+    constraints = av_hwdevice_get_hwframe_constraints(ctx->device_ref,
+                                                      hwconfig);
+    if (!constraints)
+        goto fail;
+
+    // Decide on the decoder target format.
+    // If the user specified something with -hwaccel_output_format then
+    // try to use that to minimise conversions later.
+    ctx->decode_format = AV_PIX_FMT_NONE;
+    if (ctx->output_format != AV_PIX_FMT_NONE &&
+        ctx->output_format != AV_PIX_FMT_VAAPI) {
+        for (i = 0; constraints->valid_sw_formats[i] != AV_PIX_FMT_NONE; i++) {
+            if (constraints->valid_sw_formats[i] == ctx->decode_format) {
+                ctx->decode_format = ctx->output_format;
+                av_log(ctx, AV_LOG_DEBUG, "Using decode format %s (output "
+                       "format).\n", av_get_pix_fmt_name(ctx->decode_format));
+                break;
+            }
+        }
+    }
+    // Otherwise, we would like to try to choose something which matches the
+    // decoder output, but there isn't enough information available here to
+    // do so.  Assume for now that we are always dealing with YUV 4:2:0, so
+    // pick a format which does that.
+    if (ctx->decode_format == AV_PIX_FMT_NONE) {
+        for (i = 0; constraints->valid_sw_formats[i] != AV_PIX_FMT_NONE; i++) {
+            pix_fmt  = constraints->valid_sw_formats[i];
+            pix_desc = av_pix_fmt_desc_get(pix_fmt);
+            if (pix_desc->nb_components == 3 &&
+                pix_desc->log2_chroma_w == 1 &&
+                pix_desc->log2_chroma_h == 1) {
+                ctx->decode_format = pix_fmt;
+                av_log(ctx, AV_LOG_DEBUG, "Using decode format %s (format "
+                       "matched).\n", av_get_pix_fmt_name(ctx->decode_format));
+                break;
+            }
+        }
+    }
+    // Otherwise pick the first in the list and hope for the best.
+    if (ctx->decode_format == AV_PIX_FMT_NONE) {
+        ctx->decode_format = constraints->valid_sw_formats[0];
+        av_log(ctx, AV_LOG_DEBUG, "Using decode format %s (first in list).\n",
+               av_get_pix_fmt_name(ctx->decode_format));
+        if (i > 1) {
+            // There was a choice, and we picked randomly.  Warn the user
+            // that they might want to choose intelligently instead.
+            av_log(ctx, AV_LOG_WARNING, "Using randomly chosen decode "
+                   "format %s.\n", av_get_pix_fmt_name(ctx->decode_format));
+        }
+    }
+
+    // Ensure the picture size is supported by the hardware.
+    ctx->decode_width  = avctx->coded_width;
+    ctx->decode_height = avctx->coded_height;
+    if (ctx->decode_width  < constraints->min_width  ||
+        ctx->decode_height < constraints->min_height ||
+        ctx->decode_width  > constraints->max_width  ||
+        ctx->decode_height >constraints->max_height) {
+        av_log(ctx, AV_LOG_ERROR, "VAAPI hardware does not support image "
+               "size %dx%d (constraints: width %d-%d height %d-%d).\n",
+               ctx->decode_width, ctx->decode_height,
+               constraints->min_width,  constraints->max_width,
+               constraints->min_height, constraints->max_height);
+        err = AVERROR(EINVAL);
+        goto fail;
+    }
+
+    av_hwframe_constraints_free(&constraints);
+    av_freep(&hwconfig);
+
+    // Decide how many reference frames we need.  This might be doable more
+    // nicely based on the codec and input stream?
+    ctx->decode_surfaces = DEFAULT_SURFACES;
+    // For frame-threaded decoding, one additional surfaces is needed for
+    // each thread.
+    if (avctx->active_thread_type & FF_THREAD_FRAME)
+        ctx->decode_surfaces += avctx->thread_count;
+
+    return 0;
+
+fail:
+    av_hwframe_constraints_free(&constraints);
+    av_freep(&hwconfig);
+    vaDestroyConfig(hwctx->display, ctx->va_config);
+    av_free(profile_list);
+    return err;
+}
+
+static void vaapi_decode_uninit(AVCodecContext *avctx)
+{
+    InputStream *ist = avctx->opaque;
+    VAAPIDecoderContext *ctx = ist->hwaccel_ctx;
+
+    if (ctx) {
+        AVVAAPIDeviceContext *hwctx = ctx->device->hwctx;
+
+        if (ctx->va_context != VA_INVALID_ID) {
+            vaDestroyContext(hwctx->display, ctx->va_context);
+            ctx->va_context = VA_INVALID_ID;
+        }
+        if (ctx->va_config != VA_INVALID_ID) {
+            vaDestroyConfig(hwctx->display, ctx->va_config);
+            ctx->va_config = VA_INVALID_ID;
+        }
+
+        av_buffer_unref(&ctx->frames_ref);
+        av_buffer_unref(&ctx->device_ref);
+        av_free(ctx);
+    }
+
+    av_buffer_unref(&ist->hw_frames_ctx);
+
+    ist->hwaccel_ctx           = 0;
+    ist->hwaccel_uninit        = 0;
+    ist->hwaccel_get_buffer    = 0;
+    ist->hwaccel_retrieve_data = 0;
+}
+
+int vaapi_decode_init(AVCodecContext *avctx)
+{
+    InputStream *ist = avctx->opaque;
+    AVVAAPIDeviceContext *hwctx;
+    AVVAAPIFramesContext *avfc;
+    VAAPIDecoderContext *ctx;
+    VAStatus vas;
+    int err;
+    int loglevel = (ist->hwaccel_id != HWACCEL_VAAPI ? AV_LOG_VERBOSE
+                                                     : AV_LOG_ERROR);
+
+    if (ist->hwaccel_ctx)
+        vaapi_decode_uninit(avctx);
+
+    // We have -hwaccel without -vaapi_device, so just initialise here with
+    // the device passed as -hwaccel_device (if -vaapi_device was passed, it
+    // will always have been called before now).
+    if (!hw_device_ctx) {
+        err = vaapi_device_init(ist->hwaccel_device);
+        if (err < 0)
+            return err;
+    }
+
+    ctx = av_mallocz(sizeof(*ctx));
+    if (!ctx)
+        return AVERROR(ENOMEM);
+    ctx->class = &vaapi_class;
+
+    ctx->device_ref = av_buffer_ref(hw_device_ctx);
+    ctx->device = (AVHWDeviceContext*)ctx->device_ref->data;
+
+    ctx->va_config  = VA_INVALID_ID;
+    ctx->va_context = VA_INVALID_ID;
+
+    hwctx = ctx->device->hwctx;
+
+    ctx->output_format = ist->hwaccel_output_format;
+
+    err = vaapi_build_decoder_config(ctx, avctx,
+                                     ist->hwaccel_id != HWACCEL_VAAPI);
+    if (err < 0) {
+        av_log(ctx, loglevel, "No supported configuration for this codec.");
+        goto fail;
+    }
+
+    avctx->pix_fmt = ctx->output_format;
+
+    ctx->frames_ref = av_hwframe_ctx_alloc(ctx->device_ref);
+    if (!ctx->frames_ref) {
+        av_log(ctx, loglevel, "Failed to create VAAPI frame context.\n");
+        err = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    ctx->frames = (AVHWFramesContext*)ctx->frames_ref->data;
+
+    ctx->frames->format    = AV_PIX_FMT_VAAPI;
+    ctx->frames->sw_format = ctx->decode_format;
+    ctx->frames->width     = ctx->decode_width;
+    ctx->frames->height    = ctx->decode_height;
+    ctx->frames->initial_pool_size = ctx->decode_surfaces;
+
+    err = av_hwframe_ctx_init(ctx->frames_ref);
+    if (err < 0) {
+        av_log(ctx, loglevel, "Failed to initialise VAAPI frame "
+               "context: %d\n", err);
+        goto fail;
+    }
+
+    avfc = ctx->frames->hwctx;
+
+    vas = vaCreateContext(hwctx->display, ctx->va_config,
+                          ctx->decode_width, ctx->decode_height,
+                          VA_PROGRESSIVE,
+                          avfc->surface_ids, avfc->nb_surfaces,
+                          &ctx->va_context);
+    if (vas != VA_STATUS_SUCCESS) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to create decode pipeline "
+               "context: %d (%s).\n", vas, vaErrorStr(vas));
+        err = AVERROR(EINVAL);
+        goto fail;
+    }
+
+    av_log(ctx, AV_LOG_DEBUG, "VAAPI decoder (re)init complete.\n");
+
+    // We would like to set this on the AVCodecContext for use by whoever gets
+    // the frames from the decoder, but unfortunately the AVCodecContext we
+    // have here need not be the "real" one (H.264 makes many copies for
+    // threading purposes).  To avoid the problem, we instead store it in the
+    // InputStream and propagate it from there.
+    ist->hw_frames_ctx = av_buffer_ref(ctx->frames_ref);
+    if (!ist->hw_frames_ctx) {
+        err = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    ist->hwaccel_ctx           = ctx;
+    ist->hwaccel_uninit        = vaapi_decode_uninit;
+    ist->hwaccel_get_buffer    = vaapi_get_buffer;
+    ist->hwaccel_retrieve_data = vaapi_retrieve_data;
+
+    ctx->decoder_vaapi_context.display    = hwctx->display;
+    ctx->decoder_vaapi_context.config_id  = ctx->va_config;
+    ctx->decoder_vaapi_context.context_id = ctx->va_context;
+    avctx->hwaccel_context = &ctx->decoder_vaapi_context;
+
+    return 0;
+
+fail:
+    vaapi_decode_uninit(avctx);
+    return err;
+}
+
+static AVClass *vaapi_log = &vaapi_class;
+
+static av_cold void vaapi_device_uninit(AVHWDeviceContext *hwdev)
+{
+    AVVAAPIDeviceContext *hwctx = hwdev->hwctx;
+    av_log(&vaapi_log, AV_LOG_VERBOSE, "Terminating VAAPI connection.\n");
+    vaTerminate(hwctx->display);
+}
+
+av_cold int vaapi_device_init(const char *device)
+{
+    AVHWDeviceContext    *hwdev;
+    AVVAAPIDeviceContext *hwctx;
+    VADisplay display;
+    VAStatus vas;
+    int major, minor, err;
+
+    display = 0;
+
+#if HAVE_VAAPI_X11
+    if (!display) {
+        Display *x11_display;
+
+        // Try to open the device as an X11 display.
+        x11_display = XOpenDisplay(device);
+        if (!x11_display) {
+            av_log(&vaapi_log, AV_LOG_WARNING, "Cannot open X11 display "
+                   "%s.\n", XDisplayName(device));
+        } else {
+            display = vaGetDisplay(x11_display);
+            if (!display) {
+                av_log(&vaapi_log, AV_LOG_WARNING, "Cannot open a VA display "
+                       "from X11 display %s.\n", XDisplayName(device));
+                XCloseDisplay(x11_display);
+            } else {
+                av_log(&vaapi_log, AV_LOG_VERBOSE, "Opened VA display via "
+                       "X11 display %s.\n", XDisplayName(device));
+            }
+        }
+    }
+#endif
+
+#if HAVE_VAAPI_DRM
+    if (!display && device) {
+        int drm_fd;
+
+        // Try to open the device as a DRM path.
+        drm_fd = open(device, O_RDWR);
+        if (drm_fd < 0) {
+            av_log(&vaapi_log, AV_LOG_WARNING, "Cannot open DRM device %s.\n",
+                   device);
+        } else {
+            display = vaGetDisplayDRM(drm_fd);
+            if (!display) {
+                av_log(&vaapi_log, AV_LOG_WARNING, "Cannot open a VA display "
+                       "from DRM device %s.\n", device);
+                close(drm_fd);
+            } else {
+                av_log(&vaapi_log, AV_LOG_VERBOSE, "Opened VA display via "
+                       "DRM device %s.\n", device);
+            }
+        }
+    }
+#endif
+
+    if (!display) {
+        av_log(&vaapi_log, AV_LOG_ERROR, "No VA display found for "
+               "device %s.\n", device);
+        return AVERROR(EINVAL);
+    }
+
+    vas = vaInitialize(display, &major, &minor);
+    if (vas != VA_STATUS_SUCCESS) {
+        av_log(&vaapi_log, AV_LOG_ERROR, "Failed to initialise VAAPI "
+               "connection: %d (%s).\n", vas, vaErrorStr(vas));
+        return AVERROR(EIO);
+    }
+    av_log(&vaapi_log, AV_LOG_VERBOSE, "Initialised VAAPI connection: "
+           "version %d.%d\n", major, minor);
+
+    hw_device_ctx = av_hwdevice_ctx_alloc(AV_HWDEVICE_TYPE_VAAPI);
+    if (!hw_device_ctx) {
+        av_log(&vaapi_log, AV_LOG_ERROR, "Failed to create VAAPI "
+               "hardware context.\n");
+        vaTerminate(display);
+        return AVERROR(ENOMEM);
+    }
+
+    hwdev = (AVHWDeviceContext*)hw_device_ctx->data;
+    hwdev->free = &vaapi_device_uninit;
+
+    hwctx = hwdev->hwctx;
+    hwctx->display = display;
+
+    err = av_hwdevice_ctx_init(hw_device_ctx);
+    if (err < 0) {
+        av_log(&vaapi_log, AV_LOG_ERROR, "Failed to initialise VAAPI "
+               "hardware context: %d\n", err);
+        return err;
+    }
+
+    return 0;
+}