[FFmpeg-trac] #3116(undetermined:closed): resource leaks, handle leaks(WIN7, avcodec_decode_video2, threads)

FFmpeg trac at avcodec.org
Thu Oct 1 06:04:05 CEST 2015


#3116: resource leaks,handle leaks(WIN7,avcodec_decode_video2,threads)
-------------------------------------+-------------------------------------
             Reporter:  q1q2q3q4ln   |                    Owner:
                 Type:  defect       |                   Status:  closed
             Priority:  important    |                Component:
              Version:  git-master   |  undetermined
             Keywords:  handle       |               Resolution:
  leaks                              |  needs_more_info
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------

Comment (by relwin):

 {{{
 /*
     Modified example code demuxing_decoding.c
     to expose 2 handle leaks when avcodec_decode_video2() executes within
 a thread, Bug #3116.
     Also demonstrates workaround fix, dec_ctx->thread_count = 1;
     WindowsXP/7 + SDL2.0 threads, MinGW32, GCC 4.4.3
     ffmpeg-20150919-git-8c9853a-win32-dev

     #define THD_TEST -- use threaded code
     #define THD_TEST_BUGFIX -- adds workaround

  * Copyright (c) 2012 Stefano Sabatini
  *
  * 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
  * Demuxing and decoding example.
  *
  * Show how to use the libavformat and libavcodec API to demux and
  * decode audio and video data.
  * @example demuxing_decoding.c
  */

 #include <libavutil/imgutils.h>
 #include <libavutil/samplefmt.h>
 #include <libavutil/timestamp.h>
 #include <libavformat/avformat.h>

 static AVFormatContext *fmt_ctx = NULL;
 static AVCodecContext *video_dec_ctx = NULL, *audio_dec_ctx;
 static int width, height;
 static enum AVPixelFormat pix_fmt;
 static AVStream *video_stream = NULL, *audio_stream = NULL;
 static const char *src_filename = NULL;
 static const char *video_dst_filename = NULL;
 static const char *audio_dst_filename = NULL;
 static FILE *video_dst_file = NULL;
 static FILE *audio_dst_file = NULL;

 static uint8_t *video_dst_data[4] = {NULL};
 static int      video_dst_linesize[4];
 static int video_dst_bufsize;

 static int video_stream_idx = -1, audio_stream_idx = -1;
 static AVFrame *frame = NULL;
 static AVPacket pkt;
 static int video_frame_count = 0;
 static int audio_frame_count = 0;

 /* Enable or disable frame reference counting. You are not supposed to
 support
  * both paths in your application but pick the one most appropriate to
 your
  * needs. Look for the use of refcount in this example to see what are the
  * differences of API usage between them. */
 static int refcount = 0;

 /*=================== Thread Test =======================*/
 #include <SDL2/SDL.h>
 #include <SDL2/SDL_thread.h>
 #ifdef __MINGW32__
 #undef main /* Prevents SDL from overriding main() */
 #endif
 #define THD_TEST
 #define THD_TEST_BUGFIX

 typedef int (SDLCALL *ThreadProc)(void *);

 static SDL_Thread* thread_start(ThreadProc fn, void* userdata, const char*
 name)
 {
     SDL_threadID threadID;
     SDL_assert(fn != NULL);

     SDL_Thread* thread = SDL_CreateThread(fn, name, userdata);
     if (thread == NULL)
     {
         fprintf(stderr, "SDL: Failed to run '%s' thread - %s\n", name,
 SDL_GetError());
     }
     else
     {
         threadID = SDL_GetThreadID(thread);
         fprintf(stderr,"Thread %14s ID=%08x, TID=%08x\n",name, (uint32_t)
 threadID, (uint32_t)thread);
     }
     return thread;
 }

 static int thread_wait(SDL_Thread* tid, const char* name)
 {
     int status;

     SDL_threadID threadID = SDL_GetThreadID(tid);
     fprintf(stderr,"Thread wait %14s ID=%08x, TID=%08x\n",name, (uint32_t)
 threadID, (uint32_t)tid);
     SDL_WaitThread(tid, &status);
     if(status)
     {
         fprintf(stderr,"Thread start '%s' finished with status %d\n",
 name, status);
     }
     return status;
 }
 /*=========================================*/

 static int decode_packet(int *got_frame, int cached)
 {
     int ret = 0;
     int decoded = pkt.size;

     *got_frame = 0;

     if (pkt.stream_index == video_stream_idx) {
         /* decode video frame */
         ret = avcodec_decode_video2(video_dec_ctx, frame, got_frame,
 &pkt);
         if (ret < 0) {
             fprintf(stderr, "Error decoding video frame (%s)\n",
 av_err2str(ret));
             return ret;
         }

         if (*got_frame) {

             if (frame->width != width || frame->height != height ||
                 frame->format != pix_fmt) {
                 /* To handle this change, one could call av_image_alloc
 again and
                  * decode the following frames into another rawvideo file.
 */
                 fprintf(stderr, "Error: Width, height and pixel format
 have to be "
                         "constant in a rawvideo file, but the width,
 height or "
                         "pixel format of the input video changed:\n"
                         "old: width = %d, height = %d, format = %s\n"
                         "new: width = %d, height = %d, format = %s\n",
                         width, height, av_get_pix_fmt_name(pix_fmt),
                         frame->width, frame->height,
                         av_get_pix_fmt_name(frame->format));
                 return -1;
             }

             printf("video_frame%s n:%d coded_n:%d pts:%s\n",
                    cached ? "(cached)" : "",
                    video_frame_count++, frame->coded_picture_number,
                    av_ts2timestr(frame->pts, &video_dec_ctx->time_base));

             /* copy decoded frame to destination buffer:
              * this is required since rawvideo expects non aligned data */
 #ifndef THD_TEST
         //disabled when testing
             av_image_copy(video_dst_data, video_dst_linesize,
                           (const uint8_t **)(frame->data),
 frame->linesize,
                           pix_fmt, width, height);

             // write to rawvideo file
             fwrite(video_dst_data[0], 1, video_dst_bufsize,
 video_dst_file);
 #endif // THD_TEST
         }
     } else if (pkt.stream_index == audio_stream_idx) {
         /* decode audio frame */
         ret = avcodec_decode_audio4(audio_dec_ctx, frame, got_frame,
 &pkt);
         if (ret < 0) {
             fprintf(stderr, "Error decoding audio frame (%s)\n",
 av_err2str(ret));
             return ret;
         }
         /* Some audio decoders decode only part of the packet, and have to
 be
          * called again with the remainder of the packet data.
          * Sample: fate-suite/lossless-audio/luckynight-partial.shn
          * Also, some decoders might over-read the packet. */
         decoded = FFMIN(ret, pkt.size);

         if (*got_frame) {
             size_t unpadded_linesize = frame->nb_samples *
 av_get_bytes_per_sample(frame->format);
             printf("audio_frame%s n:%d nb_samples:%d pts:%s\n",
                    cached ? "(cached)" : "",
                    audio_frame_count++, frame->nb_samples,
                    av_ts2timestr(frame->pts, &audio_dec_ctx->time_base));

             /* Write the raw audio data samples of the first plane. This
 works
              * fine for packed formats (e.g. AV_SAMPLE_FMT_S16). However,
              * most audio decoders output planar audio, which uses a
 separate
              * plane of audio samples for each channel (e.g.
 AV_SAMPLE_FMT_S16P).
              * In other words, this code will write only the first audio
 channel
              * in these cases.
              * You should use libswresample or libavfilter to convert the
 frame
              * to packed data. */
 #ifndef THD_TEST
             //disabled when testing
             fwrite(frame->extended_data[0], 1, unpadded_linesize,
 audio_dst_file);
 #endif // THD_TEST
         }
     }

     /* If we use frame reference counting, we own the data and need
      * to de-reference it when we don't use it anymore */
     if (*got_frame && refcount)
         av_frame_unref(frame);

     return decoded;
 }



 //sample task to decode
 static int demux_thread_test(void* arg)
 {
     int ret = 0, got_frame;
 //return 0;                     //ignore decoding to test

     /* read frames from the file */
     while (av_read_frame(fmt_ctx, &pkt) >= 0) {
         AVPacket orig_pkt = pkt;
         do {
             ret = decode_packet(&got_frame, 0);
             if (ret < 0)
                 break;
             pkt.data += ret;
             pkt.size -= ret;
         } while (pkt.size > 0);
         av_free_packet(&orig_pkt);
     }

     /* flush cached frames */
     pkt.data = NULL;
     pkt.size = 0;
     do {
         decode_packet(&got_frame, 1);
     } while (got_frame);

     return 0;
 }



 static int open_codec_context(int *stream_idx,
                               AVFormatContext *fmt_ctx, enum AVMediaType
 type)
 {
     int ret, stream_index;
     AVStream *st;
     AVCodecContext *dec_ctx = NULL;
     AVCodec *dec = NULL;
     AVDictionary *opts = NULL;

     ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);
     if (ret < 0) {
         fprintf(stderr, "Could not find %s stream in input file '%s'\n",
                 av_get_media_type_string(type), src_filename);
         return ret;
     } else {
         stream_index = ret;
         st = fmt_ctx->streams[stream_index];

         /* find decoder for the stream */
         dec_ctx = st->codec;
         dec = avcodec_find_decoder(dec_ctx->codec_id);
         if (!dec) {
             fprintf(stderr, "Failed to find %s codec\n",
                     av_get_media_type_string(type));
             return AVERROR(EINVAL);
         }

         /* Init the decoders, with or without reference counting */
         av_dict_set(&opts, "refcounted_frames", refcount ? "1" : "0", 0);

 #ifdef THD_TEST_BUGFIX
         dec_ctx->thread_count = 1;  //this fixes thread bug
 #endif // THD_TEST_BUGFIX

         if ((ret = avcodec_open2(dec_ctx, dec, &opts)) < 0) {
             fprintf(stderr, "Failed to open %s codec\n",
                     av_get_media_type_string(type));
             return ret;
         }
         *stream_idx = stream_index;
     }

     return 0;
 }





 static int get_format_from_sample_fmt(const char **fmt,
                                       enum AVSampleFormat sample_fmt)
 {
     int i;
     struct sample_fmt_entry {
         enum AVSampleFormat sample_fmt; const char *fmt_be, *fmt_le;
     } sample_fmt_entries[] = {
         { AV_SAMPLE_FMT_U8,  "u8",    "u8"    },
         { AV_SAMPLE_FMT_S16, "s16be", "s16le" },
         { AV_SAMPLE_FMT_S32, "s32be", "s32le" },
         { AV_SAMPLE_FMT_FLT, "f32be", "f32le" },
         { AV_SAMPLE_FMT_DBL, "f64be", "f64le" },
     };
     *fmt = NULL;

     for (i = 0; i < FF_ARRAY_ELEMS(sample_fmt_entries); i++) {
         struct sample_fmt_entry *entry = &sample_fmt_entries[i];
         if (sample_fmt == entry->sample_fmt) {
             *fmt = AV_NE(entry->fmt_be, entry->fmt_le);
             return 0;
         }
     }

     fprintf(stderr,
             "sample format %s is not supported as output format\n",
             av_get_sample_fmt_name(sample_fmt));
     return -1;
 }



 int main (int argc, char **argv)
 {
     int ret = 0, got_frame;

     if (argc != 4 && argc != 5) {
         fprintf(stderr, "usage: %s [-refcount] input_file
 video_output_file audio_output_file\n"
                 "API example program to show how to read frames from an
 input file.\n"
                 "This program reads frames from a file, decodes them, and
 writes decoded\n"
                 "video frames to a rawvideo file named video_output_file,
 and decoded\n"
                 "audio frames to a rawaudio file named
 audio_output_file.\n\n"
                 "If the -refcount option is specified, the program use
 the\n"
                 "reference counting frame system which allows keeping a
 copy of\n"
                 "the data for longer than one decode call.\n"
                 "\n", argv[0]);
         exit(1);
     }
     if (argc == 5 && !strcmp(argv[1], "-refcount")) {
         refcount = 1;
         argv++;
     }
     src_filename = argv[1];
     video_dst_filename = argv[2];
     audio_dst_filename = argv[3];

     /* register all formats and codecs */
     av_register_all();

     /* open input file, and allocate format context */
     if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {
         fprintf(stderr, "Could not open source file %s\n", src_filename);
         exit(1);
     }

     /* retrieve stream information */
     if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {
         fprintf(stderr, "Could not find stream information\n");
         exit(1);
     }

     if (open_codec_context(&video_stream_idx, fmt_ctx, AVMEDIA_TYPE_VIDEO)
 >= 0) {
         video_stream = fmt_ctx->streams[video_stream_idx];
         video_dec_ctx = video_stream->codec;

         video_dst_file = fopen(video_dst_filename, "wb");
         if (!video_dst_file) {
             fprintf(stderr, "Could not open destination file %s\n",
 video_dst_filename);
             ret = 1;
             goto end;
         }

         /* allocate image where the decoded image will be put */
         width = video_dec_ctx->width;
         height = video_dec_ctx->height;
         pix_fmt = video_dec_ctx->pix_fmt;
         ret = av_image_alloc(video_dst_data, video_dst_linesize,
                              width, height, pix_fmt, 1);
         if (ret < 0) {
             fprintf(stderr, "Could not allocate raw video buffer\n");
             goto end;
         }
         video_dst_bufsize = ret;
     }

     if (open_codec_context(&audio_stream_idx, fmt_ctx, AVMEDIA_TYPE_AUDIO)
 >= 0) {
         audio_stream = fmt_ctx->streams[audio_stream_idx];
         audio_dec_ctx = audio_stream->codec;
         audio_dst_file = fopen(audio_dst_filename, "wb");
         if (!audio_dst_file) {
             fprintf(stderr, "Could not open destination file %s\n",
 audio_dst_filename);
             ret = 1;
             goto end;
         }
     }

     /* dump input information to stderr */
     av_dump_format(fmt_ctx, 0, src_filename, 0);

     if (!audio_stream && !video_stream) {
         fprintf(stderr, "Could not find audio or video stream in the
 input, aborting\n");
         ret = 1;
         goto end;
     }

     frame = av_frame_alloc();
     if (!frame) {
         fprintf(stderr, "Could not allocate frame\n");
         ret = AVERROR(ENOMEM);
         goto end;
     }

     /* initialize packet, set data to NULL, let the demuxer fill it */
     av_init_packet(&pkt);
     pkt.data = NULL;
     pkt.size = 0;

     if (video_stream)
         printf("Demuxing video from file '%s' into '%s'\n", src_filename,
 video_dst_filename);
     if (audio_stream)
         printf("Demuxing audio from file '%s' into '%s'\n", src_filename,
 audio_dst_filename);

 #ifndef THD_TEST
     /* read frames from the file */
     while (av_read_frame(fmt_ctx, &pkt) >= 0) {
         AVPacket orig_pkt = pkt;
         do {
             ret = decode_packet(&got_frame, 0);
             if (ret < 0)
                 break;
             pkt.data += ret;
             pkt.size -= ret;
         } while (pkt.size > 0);
         av_free_packet(&orig_pkt);
     }

     /* flush cached frames */
     pkt.data = NULL;
     pkt.size = 0;
     do {
         decode_packet(&got_frame, 1);
     } while (got_frame);
 #endif
 #ifdef THD_TEST
     // SDL setup, only threads used
     if( SDL_Init(0))
     {
         fprintf(stderr, "Could not initialize SDL - %s\n",
 SDL_GetError());
         exit(1);
     }

     SDL_Thread* demux_tid;
     demux_tid = thread_start( demux_thread_test, NULL, "decodetest");
     thread_wait(demux_tid, "decodetest");
 #endif // THD_TEST

     printf("Demuxing succeeded.\n");

     if (video_stream) {
         printf("Play the output video file with the command:\n"
                "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n",
                av_get_pix_fmt_name(pix_fmt), width, height,
                video_dst_filename);
     }

     if (audio_stream) {
         enum AVSampleFormat sfmt = audio_dec_ctx->sample_fmt;
         int n_channels = audio_dec_ctx->channels;
         const char *fmt;

         if (av_sample_fmt_is_planar(sfmt)) {
             const char *packed = av_get_sample_fmt_name(sfmt);
             printf("Warning: the sample format the decoder produced is
 planar "
                    "(%s). This example will output the first channel
 only.\n",
                    packed ? packed : "?");
             sfmt = av_get_packed_sample_fmt(sfmt);
             n_channels = 1;
         }

         if ((ret = get_format_from_sample_fmt(&fmt, sfmt)) < 0)
             goto end;

         printf("Play the output audio file with the command:\n"
                "ffplay -f %s -ac %d -ar %d %s\n",
                fmt, n_channels, audio_dec_ctx->sample_rate,
                audio_dst_filename);
     }

 end:
     avcodec_close(video_dec_ctx);
     avcodec_close(audio_dec_ctx);
     avformat_close_input(&fmt_ctx);
     if (video_dst_file)
         fclose(video_dst_file);
     if (audio_dst_file)
         fclose(audio_dst_file);
     av_frame_free(&frame);
     av_free(video_dst_data[0]);

     return ret < 0;
 }

 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/3116#comment:12>
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