[FFmpeg-devel] [PATCH V2] examples/vaapi_dec_scaling: add a vaapi decoding/scaling sample

Jun Zhao mypopydev at gmail.com
Thu Aug 23 16:08:01 EEST 2018


add a vaapi decoding/scaling sample.

Signed-off-by: Jun Zhao <mypopydev at gmail.com>
---
 configure                        |    2 +
 doc/examples/Makefile            |    1 +
 doc/examples/vaapi_dec_scaling.c |  377 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 380 insertions(+), 0 deletions(-)
 create mode 100644 doc/examples/vaapi_dec_scaling.c

diff --git a/configure b/configure
index 9b5421d..77ed4bf 100755
--- a/configure
+++ b/configure
@@ -1612,6 +1612,7 @@ EXAMPLE_LIST="
     scaling_video_example
     transcode_aac_example
     transcoding_example
+    vaapi_dec_scaling_example
     vaapi_encode_example
     vaapi_transcode_example
 "
@@ -3461,6 +3462,7 @@ resampling_audio_example_deps="avutil swresample"
 scaling_video_example_deps="avutil swscale"
 transcode_aac_example_deps="avcodec avformat swresample"
 transcoding_example_deps="avfilter avcodec avformat avutil"
+vaapi_dec_scaling_example_deps="avfilter avcodec avformat avutil"
 vaapi_encode_example_deps="avcodec avutil h264_vaapi_encoder"
 vaapi_transcode_example_deps="avcodec avformat avutil h264_vaapi_encoder"
 
diff --git a/doc/examples/Makefile b/doc/examples/Makefile
index 928ff30..3ea6899 100644
--- a/doc/examples/Makefile
+++ b/doc/examples/Makefile
@@ -19,6 +19,7 @@ EXAMPLES-$(CONFIG_RESAMPLING_AUDIO_EXAMPLE)  += resampling_audio
 EXAMPLES-$(CONFIG_SCALING_VIDEO_EXAMPLE)     += scaling_video
 EXAMPLES-$(CONFIG_TRANSCODE_AAC_EXAMPLE)     += transcode_aac
 EXAMPLES-$(CONFIG_TRANSCODING_EXAMPLE)       += transcoding
+EXAMPLES-$(CONFIG_VAAPI_DEC_SCALING_EXAMPLE) += vaapi_dec_scaling
 EXAMPLES-$(CONFIG_VAAPI_ENCODE_EXAMPLE)      += vaapi_encode
 EXAMPLES-$(CONFIG_VAAPI_TRANSCODE_EXAMPLE)   += vaapi_transcode
 
diff --git a/doc/examples/vaapi_dec_scaling.c b/doc/examples/vaapi_dec_scaling.c
new file mode 100644
index 0000000..30aa163
--- /dev/null
+++ b/doc/examples/vaapi_dec_scaling.c
@@ -0,0 +1,377 @@
+/*
+ * Copyright (c) 2018 Jun Zhao
+ *
+ * VA-API Acceleration API (video decoding/scaling) sample
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * @file
+ * VA-API-Accelerated decoding/scaling example.
+ *
+ * @example vaapi_dec_scaling.c
+ * This example shows how to do VA-API-accelerated decoding/scaling with output
+ * frames from the HW video surfaces.
+ */
+
+#include <stdio.h>
+
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+#include <libavfilter/buffersink.h>
+#include <libavfilter/buffersrc.h>
+#include <libavutil/pixdesc.h>
+#include <libavutil/hwcontext.h>
+#include <libavutil/opt.h>
+#include <libavutil/avassert.h>
+#include <libavutil/imgutils.h>
+
+static AVBufferRef *hw_device_ctx = NULL;
+static enum AVPixelFormat hw_pix_fmt;
+static FILE *output_file = NULL;
+AVFilterContext *buffersink_ctx;
+AVFilterContext *buffersrc_ctx;
+AVFilterGraph *filter_graph;
+const char *filter_descr =
+    "format=vaapi,scale_vaapi=w=iw/2:h=ih/2,hwdownload,format=nv12";
+int init_filter = 0;
+
+static int init_hw_decode(AVCodecContext *ctx, const enum AVHWDeviceType type)
+{
+    int err = 0;
+
+    if ((err = av_hwdevice_ctx_create(&hw_device_ctx, type,
+                                      NULL, NULL, 0)) < 0) {
+        fprintf(stderr, "Failed to create specified HW device.\n");
+        return err;
+    }
+    ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
+
+    return err;
+}
+
+static int init_filters(AVFormatContext *fmt_ctx, AVCodecContext *dec_ctx,
+                        int video_stream_index, const char *filters_descr)
+{
+    char args[512];
+    int ret = 0;
+    const AVFilter *buffersrc  = avfilter_get_by_name("buffer");
+    const AVFilter *buffersink = avfilter_get_by_name("buffersink");
+    AVFilterInOut *outputs = avfilter_inout_alloc();
+    AVFilterInOut *inputs  = avfilter_inout_alloc();
+    AVRational time_base = fmt_ctx->streams[video_stream_index]->time_base;
+    AVBufferSrcParameters *par = av_buffersrc_parameters_alloc();
+
+    filter_graph = avfilter_graph_alloc();
+    if (!outputs || !inputs || !filter_graph || !par) {
+        ret = AVERROR(ENOMEM);
+        goto end;
+    }
+
+    /* buffer video source: the decoded frames from the decoder will be inserted here. */
+    snprintf(args, sizeof(args),
+            "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
+            dec_ctx->width, dec_ctx->height, AV_PIX_FMT_VAAPI,
+            time_base.num, time_base.den,
+            dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den);
+
+    ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
+                                       args, NULL, filter_graph);
+    if (ret < 0) {
+        fprintf(stderr, "Cannot create buffer source\n");
+        goto end;
+    }
+    par->hw_frames_ctx = dec_ctx->hw_frames_ctx;
+    ret = av_buffersrc_parameters_set(buffersrc_ctx, par);
+    if (ret < 0)
+        goto end;
+    av_freep(&par);
+
+    /* buffer video sink: to terminate the filter chain. */
+    ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
+                                       NULL, NULL, filter_graph);
+    if (ret < 0) {
+        fprintf(stderr, "Cannot create buffer sink\n");
+        goto end;
+    }
+
+    /*
+     * Set the endpoints for the filter graph. The filter_graph will
+     * be linked to the graph described by filters_descr.
+     */
+
+    /*
+     * The buffer source output must be connected to the input pad of
+     * the first filter described by filters_descr; since the first
+     * filter input label is not specified, it is set to "in" by
+     * default.
+     */
+    outputs->name       = av_strdup("in");
+    outputs->filter_ctx = buffersrc_ctx;
+    outputs->pad_idx    = 0;
+    outputs->next       = NULL;
+
+    /*
+     * The buffer sink input must be connected to the output pad of
+     * the last filter described by filters_descr; since the last
+     * filter output label is not specified, it is set to "out" by
+     * default.
+     */
+    inputs->name       = av_strdup("out");
+    inputs->filter_ctx = buffersink_ctx;
+    inputs->pad_idx    = 0;
+    inputs->next       = NULL;
+
+    if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr,
+                                        &inputs, &outputs, NULL)) < 0)
+        goto end;
+
+    for (int i = 0; i < filter_graph->nb_filters; i++) {
+        filter_graph->filters[i]->hw_device_ctx = av_buffer_ref(hw_device_ctx);
+        if (!filter_graph->filters[i]->hw_device_ctx) {
+            ret = AVERROR(ENOMEM);
+            goto end;
+        }
+    }
+
+    if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
+        goto end;
+
+end:
+    avfilter_inout_free(&inputs);
+    avfilter_inout_free(&outputs);
+
+    return ret;
+}
+
+static enum AVPixelFormat get_hw_format(AVCodecContext *ctx,
+                                        const enum AVPixelFormat *pix_fmts)
+{
+    const enum AVPixelFormat *p;
+
+    for (p = pix_fmts; *p != -1; p++) {
+        if (*p == hw_pix_fmt)
+            return *p;
+    }
+
+    fprintf(stderr, "Failed to get HW surface format.\n");
+    return AV_PIX_FMT_NONE;
+}
+
+static int decode_filte(AVFormatContext *input_ctx, AVCodecContext *avctx,
+                        int video_stream, AVPacket *packet)
+{
+    AVFrame *frame = NULL;
+    AVFrame *filt_frame = NULL;
+    uint8_t *buffer = NULL;
+    int size;
+    int ret = 0;
+
+    ret = avcodec_send_packet(avctx, packet);
+    if (ret < 0) {
+        fprintf(stderr, "Error during decoding\n");
+        return ret;
+    }
+
+    frame = av_frame_alloc();
+    filt_frame = av_frame_alloc();
+    if (!frame || !filt_frame) {
+        fprintf(stderr, "Can not alloc frame\n");
+        ret = AVERROR(ENOMEM);
+        return ret;
+    }
+
+    while (1) {
+        ret = avcodec_receive_frame(avctx, frame);
+        if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
+            av_frame_free(&frame);
+            av_frame_free(&filt_frame);
+            return 0;
+        } else if (ret < 0) {
+            fprintf(stderr, "Error while decoding\n");
+            goto fail;
+        }
+
+        if (frame->format == hw_pix_fmt) {
+            if (!init_filter) {
+                if ((ret = init_filters(input_ctx, avctx,
+                                        video_stream, filter_descr)) < 0) {
+                    fprintf(stderr, "Failed to init filter\n");
+                    goto fail;
+                }
+                init_filter = 1;
+            }
+
+            /* push the decoded frame into the filtergraph */
+            if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF) < 0) {
+                av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
+                goto fail;
+            }
+
+            /* pull filtered frames from the filtergraph */
+            while (1) {
+                ret = av_buffersink_get_frame(buffersink_ctx, filt_frame);
+                if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
+                    break;
+                if (ret < 0)
+                    goto fail;
+
+                size = av_image_get_buffer_size(filt_frame->format, filt_frame->width,
+                                                filt_frame->height, 1);
+                buffer = av_malloc(size);
+                if (!buffer) {
+                    fprintf(stderr, "Can not alloc buffer\n");
+                    ret = AVERROR(ENOMEM);
+                    goto fail;
+                }
+                ret = av_image_copy_to_buffer(buffer, size,
+                                              (const uint8_t * const *)filt_frame->data,
+                                              (const int *)filt_frame->linesize, filt_frame->format,
+                                              filt_frame->width, filt_frame->height, 1);
+                if (ret < 0) {
+                    fprintf(stderr, "Can not copy image to buffer\n");
+                    goto fail;
+                }
+
+                if ((ret = fwrite(buffer, 1, size, output_file)) < 0) {
+                    fprintf(stderr, "Failed to dump filted raw data.\n");
+                    goto fail;
+                }
+
+                av_frame_unref(filt_frame);
+                av_freep(&buffer);
+            }
+            av_frame_unref(frame);
+        }
+    }
+
+fail:
+    av_frame_free(&frame);
+    av_frame_free(&filt_frame);
+    av_freep(&buffer);
+
+    return ret;
+}
+
+int main(int argc, char *argv[])
+{
+    AVFormatContext *input_ctx = NULL;
+    int video_stream, ret;
+    AVStream *video = NULL;
+    AVCodecContext *decoder_ctx = NULL;
+    AVCodec *decoder = NULL;
+    AVPacket packet;
+    enum AVHWDeviceType type;
+    int i;
+
+    if (argc < 3) {
+        fprintf(stderr, "Usage: %s <input file> <output file>\n", argv[0]);
+        return -1;
+    }
+
+    type = av_hwdevice_find_type_by_name("vaapi");
+    if (type == AV_HWDEVICE_TYPE_NONE) {
+        fprintf(stderr, "Device type vaapi is not supported.\n");
+        fprintf(stderr, "Available device types:");
+        while((type = av_hwdevice_iterate_types(type)) != AV_HWDEVICE_TYPE_NONE)
+            fprintf(stderr, " %s", av_hwdevice_get_type_name(type));
+        fprintf(stderr, "\n");
+        return -1;
+    }
+
+    /* open the input file */
+    if (avformat_open_input(&input_ctx, argv[1], NULL, NULL) != 0) {
+        fprintf(stderr, "Cannot open input file '%s'\n", argv[2]);
+        return -1;
+    }
+
+    if (avformat_find_stream_info(input_ctx, NULL) < 0) {
+        fprintf(stderr, "Cannot find input stream information.\n");
+        return -1;
+    }
+
+    /* find the video stream information */
+    ret = av_find_best_stream(input_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &decoder, 0);
+    if (ret < 0) {
+        fprintf(stderr, "Cannot find a video stream in the input file\n");
+        return -1;
+    }
+    video_stream = ret;
+
+    for (i = 0;; i++) {
+        const AVCodecHWConfig *config = avcodec_get_hw_config(decoder, i);
+        if (!config) {
+            fprintf(stderr, "Decoder %s does not support device type %s.\n",
+                    decoder->name, av_hwdevice_get_type_name(type));
+            return -1;
+        }
+        if (config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX &&
+            config->device_type == type) {
+            hw_pix_fmt = config->pix_fmt;
+            break;
+        }
+    }
+
+    if (!(decoder_ctx = avcodec_alloc_context3(decoder)))
+        return AVERROR(ENOMEM);
+
+    video = input_ctx->streams[video_stream];
+    if (avcodec_parameters_to_context(decoder_ctx, video->codecpar) < 0)
+        return -1;
+
+    decoder_ctx->get_format  = get_hw_format;
+
+    if (init_hw_decode(decoder_ctx, type) < 0)
+        return -1;
+
+    if ((ret = avcodec_open2(decoder_ctx, decoder, NULL)) < 0) {
+        fprintf(stderr, "Failed to open codec for stream #%u\n", video_stream);
+        return -1;
+    }
+
+    /* open the file to dump scaled data */
+    output_file = fopen(argv[2], "w+");
+
+    /* actual decoding/scaling and dump the raw data */
+    while (ret >= 0) {
+        if ((ret = av_read_frame(input_ctx, &packet)) < 0)
+            break;
+
+        if (video_stream == packet.stream_index)
+            ret = decode_filte(input_ctx, decoder_ctx, video_stream, &packet);
+
+        av_packet_unref(&packet);
+    }
+
+    /* flush the decoder/avfilter */
+    packet.data = NULL;
+    packet.size = 0;
+    ret = decode_filte(input_ctx, decoder_ctx, video_stream, &packet);
+    av_packet_unref(&packet);
+
+    if (output_file)
+        fclose(output_file);
+    avfilter_graph_free(&filter_graph);
+    avcodec_free_context(&decoder_ctx);
+    avformat_close_input(&input_ctx);
+    av_buffer_unref(&hw_device_ctx);
+
+    return 0;
+}
-- 
1.7.1



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