On 17/07/17 03:51, Jun Zhao wrote> On 2017/7/11 15:58, wm4 wrote: >> On Tue, 11 Jul 2017 12:06:10 +0800 >> Jun Zhao <mypopy...@gmail.com> wrote: >> >>> From 0e4d230ae4c98949a962c6bbdad31d216b54bb6a Mon Sep 17 00:00:00 2001 >>> From: Jun Zhao <jun.z...@intel.com> >>> Date: Tue, 21 Mar 2017 11:04:41 +0800 >>> Subject: [V2] examples/vaapi_dec: Add a VA-API hwaccel decoding example. >>> >>> Add a VA-API hwaccel decoding example. >>> >>> Signed-off-by: Liu, Kaixuan <kaixuan....@intel.com> >>> Signed-off-by: Jun Zhao <jun.z...@intel.com> >>> --- >>> doc/examples/vaapi_dec.c | 266 >>> +++++++++++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 266 insertions(+) >>> create mode 100644 doc/examples/vaapi_dec.c >>> >>> diff --git a/doc/examples/vaapi_dec.c b/doc/examples/vaapi_dec.c >>> new file mode 100644 >>> index 0000000000..01320a3b71 >>> --- /dev/null >>> +++ b/doc/examples/vaapi_dec.c >>> @@ -0,0 +1,266 @@ >>> +/* >>> + * Video Acceleration API (video decoding) decode sample >>> + * >>> + * 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 >>> + */ >>> + >>> +/** >>> + * @file >>> + * Intel VAAPI-accelerated decoding example. >>> + * >>> + * @example vaapi_dec.c >>> + * This example shows how to do VAAPI-accelerated decoding with output >>> + * frames from the VAAPI video surfaces. >>> + */ >>> + >>> +#include <stdio.h> >>> +#include <libavcodec/avcodec.h> >>> +#include <libavcodec/vaapi.h>
This file is deprecated, and contains nothing useful anyway. >>> +#include <libavformat/avformat.h> >>> +#include <libavutil/pixdesc.h> >>> +#include <libavutil/hwcontext.h> >>> +#include <libavutil/opt.h> >>> +#include <libavutil/hwcontext_vaapi.h> Shouldn't need any of the API-specific hwcontext includes, just the generic one. >>> +#include <libavutil/avassert.h> >>> + >>> +static AVBufferRef *hw_device_ctx = NULL; >>> +FILE *output_file = NULL; >>> + >>> +int decoder_init_vaapi(AVCodecContext *ctx) >>> +{ >>> + int err = 0; >>> + const char *dev_name = "/dev/dri/renderD128"; >>> + >>> + if ((err = av_hwdevice_ctx_create(&hw_device_ctx, >>> AV_HWDEVICE_TYPE_VAAPI, >>> + dev_name, NULL, 0)) < 0) { >> >> The implementation already uses your dev_name as default, so you should >> be able to drop that, and pass NULL to it. >> > > Yes, will remove the dev_name. > >>> + fprintf(stderr, "Failed to create a VAAPI device.\n"); >>> + return err; >>> + } >>> + ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx); >>> + >>> + return err; >>> +} >>> + >>> +static enum AVPixelFormat get_vaapi_format(AVCodecContext *ctx, >>> + const enum AVPixelFormat >>> *pix_fmts) >>> +{ >>> + const enum AVPixelFormat *p; >>> + >>> + for (p = pix_fmts; *p != -1; p++) { >>> + if (*p == AV_PIX_FMT_VAAPI) >>> + return *p; >>> + } >>> + >>> + return AV_PIX_FMT_NONE; >>> +} >>> + >>> +int retrieve_data(AVFrame *input) >>> +{ >>> + AVFrame *output = NULL; >>> + int err; >>> + av_assert0(input->format == AV_PIX_FMT_VAAPI); >>> + >>> + if (!(output = av_frame_alloc())) >>> + return AVERROR(ENOMEM); >>> + /* default output nv12 */ >>> + output->format = AV_PIX_FMT_NV12; >> >> You could use av_hwframe_transfer_get_formats() instead of hardcoding >> it. Might be better if the input is 10 bit, not sure. (Just a >> suggestion, up to you.) > Ok, it's will show the HW surface/ SW pixel format mapping if we > use av_hwframe_transfer_get_formats() instead of hardcoding. > >> >>> + if ((err = av_hwframe_transfer_data(output, input, 0)) < 0) { >>> + fprintf(stderr, "Failed to transfer data to output frame: %d.\n", >>> err); >>> + goto fail; >>> + } >>> + >>> + if ((err = av_frame_copy_props(output, input)) < 0) { >>> + av_frame_unref(output); >>> + goto fail; >>> + } >>> + >>> + av_frame_unref(input); >>> + av_frame_move_ref(input, output); >>> + av_frame_free(&output); >>> + return 0; >>> + >>> +fail: >>> + av_frame_free(&output); >>> + return err; >>> +} >>> + >>> +int write_frame(AVFrame *frame) >>> +{ >>> + int idx, size; >>> + int width = frame->width; >>> + int height = frame->height; >>> + >>> + av_assert0(frame && frame->data[0] && output_file); >>> + >>> + for (idx = 0; idx < height; idx++) { >>> + if ((size = fwrite(frame->data[0] + idx*frame->linesize[0], >>> + 1, width, output_file)) < 0) { >>> + fprintf(stderr, "Dump Y to file error.\n"); >>> + return -1; >>> + } >>> + } >>> + >>> + height >>= 1; >>> + for (idx = 0; idx < height; idx++) { >>> + if ((size = fwrite(frame->data[1] + idx*frame->linesize[1], >>> + 1, width, output_file)) < 0) { >>> + fprintf(stderr, "Dump UV to file error.\n"); >>> + return -1; >>> + } >>> + } >> >> Using av_image_copy_to_buffer() would be more generic, although it'd >> require another allocation/copy in memory. (Just a suggestion.) >> > Will use av_image_copy_to_buffer(). > >>> + >>> + return 0; >>> +} >>> + >>> +int decode_write(AVCodecContext *avctx, AVPacket packet, int flush) I don't think you mean to pass the packet by value here. >>> +{ >>> + AVFrame *frame = NULL; >>> + int ret = 0; >>> + >>> + ret = avcodec_send_packet(avctx, &packet); >>> + if (ret < 0 && ret != AVERROR_EOF) >>> + return 0; >>> + >>> + if (!(frame = av_frame_alloc())) >>> + return AVERROR(ENOMEM); >>> + >>> + ret = avcodec_receive_frame(avctx, frame); >>> + if (ret >= 0) { >>> + /* retrieve data from GPU to CPU */ >>> + if ((ret = retrieve_data(frame)) < 0) >>> + goto fail; >>> + >>> + if ((ret = write_frame(frame)) < 0) >>> + goto fail; >>> + } else if (flush == 0) { >>> + ret = 0; >>> + } >>> + >>> +fail: >>> + av_frame_free(&frame); >>> + return ret; >>> +} >>> + >>> +/* flush the decoder */ >>> +int flush(AVCodecContext *avctx) >>> +{ >>> + AVPacket packet; >>> + int ret = 0; >>> + >>> + av_init_packet(&packet); >>> + packet.data = NULL; >>> + packet.size = 0; IIRC passing NULL directly to avcodec_send_packet() is preferable to an empty packet to flush? >>> + >>> + while (1) { >>> + if ((ret = decode_write(avctx, packet, 1)) < 0) >>> + break; >>> + } >>> + av_packet_unref(&packet); >>> + >>> + return 0; >>> +} >>> + >>> +int main(int argc, char *argv[]) >>> +{ >>> + AVFormatContext *input_ctx = NULL; >>> + int i, video_stream, ret; >>> + AVCodecContext *decoder_ctx = NULL; >>> + AVCodec *decoder = NULL; >>> + AVPacket packet; >>> + >>> + if (argc < 3) { >>> + fprintf(stderr, "Usage: %s <input file> <output file>\n", argv[0]); >>> + return -1; >>> + } >>> + >>> + av_register_all(); >>> + >>> + /* open the input file */ >>> + if (avformat_open_input(&input_ctx, argv[1], NULL, NULL) != 0) { >>> + fprintf(stderr, "Cannot open input file '%s'\n", argv[1]); >>> + return -1; >>> + } >>> + >>> + if (avformat_find_stream_info(input_ctx, NULL) < 0) { >>> + fprintf(stderr, "Couldn't find input stream information.\n"); >>> + goto fail; >>> + } >>> + >>> + /* find the video stream information */ >>> + video_stream = -1; >>> + for (i = 0; i < input_ctx->nb_streams; i++) { >>> + AVStream *st = input_ctx->streams[i]; >>> + if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) { >>> + video_stream = i; /* NOTE: just handle the first video >>> stream */ >>> + break; >>> + } >>> + } Maybe replace this block with av_find_best_stream()? (Assuming there isn't some reason I'm missing that that doesn't work...) >>> + >>> + if (video_stream == -1) { >>> + fprintf(stderr, "No find a video stream in the input file.\n"); >>> + goto fail; >>> + } >>> + >>> + /* initialize the video decoder */ >>> + if (!(decoder = >>> avcodec_find_decoder(input_ctx->streams[video_stream]->codecpar->codec_id))) >>> { >>> + fprintf(stderr, "Could not find input codec\n"); >>> + goto fail; >>> + } >>> + >>> + if (!(decoder_ctx = avcodec_alloc_context3(decoder))) >>> + return AVERROR(ENOMEM); >>> + >>> + if (avcodec_parameters_to_context(decoder_ctx, >>> + >>> input_ctx->streams[video_stream]->codecpar) < 0) >>> + goto fail; >>> + >>> + decoder_ctx->get_format = get_vaapi_format; >>> + av_opt_set_int(decoder_ctx, "refcounted_frames", 1, 0); >>> + >>> + if (decoder_init_vaapi(decoder_ctx) < 0) >>> + goto fail; >>> + >>> + if ((ret = avcodec_open2(decoder_ctx, decoder, NULL)) < 0) { >>> + fprintf(stderr, "Failed to open codec for stream #%u\n", i); >>> + goto fail; >>> + } >>> + >>> + /* open the output file to dump YUV */ >>> + output_file = fopen(argv[2], "w+"); >>> + >>> + /* actual decoding and dump the YUV data */ >>> + while (av_read_frame(input_ctx, &packet) >= 0) { >>> + if (video_stream == packet.stream_index) >>> + ret = decode_write(decoder_ctx, packet, 0); >>> + av_packet_unref(&packet); >>> + >>> + if (ret < 0) >>> + break; >>> + } >>> + >>> + /* flush the decoder */ >>> + flush(decoder_ctx); >>> + >>> +fail: >>> + if (output_file) >>> + fclose(output_file); >>> + avcodec_free_context(&decoder_ctx); >>> + avformat_close_input(&input_ctx); >>> + av_buffer_unref(&hw_device_ctx); >>> + >>> + return ret; >>> +} >> >> Generally looks OK. Can you replace all references to "vaapi" with "hw" >> or so? This code will work for other hwaccels too, and the only things >> that need to be switched are the AV_HWDEVICE_TYPE and the decoding >> AVPixelFormat. The pixel format still needs to be mapped manually, but >> we hope to add new API to make this also generic, so in the end you >> could choose the hw implementation by passing a name to it or fully >> automatically or so. > > Good suggestion, will re-work for the general HWAccel decode sample. Agree. Maybe pass the type name as a first argument to make the command line like "argv[0] <vaapi|dxva2|d3d11va> <input file> <output file>"? (Those three should work at least. Videotoolbox might work as well, VDPAU would need different output formats. Probably don't want more complexity than that, though, because it wants to be a clear example.) Rest looks good to me. Thanks, - Mark _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel