The Tor Browser: content/media/fmp4/ffmpeg/FFmpegDataDecoder.cpp@a63d609f5ebe

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* vim:set ts=2 sw=2 sts=2 et cindent: */

     3 /* This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #include <string.h>

     8 #include <unistd.h>

    10 #include "MediaTaskQueue.h"

    11 #include "mp4_demuxer/mp4_demuxer.h"

    12 #include "FFmpegRuntimeLinker.h"

    14 #include "FFmpegDataDecoder.h"

    16 namespace mozilla

    17 {

    19 bool FFmpegDataDecoder::sFFmpegInitDone = false;

    21 FFmpegDataDecoder::FFmpegDataDecoder(MediaTaskQueue* aTaskQueue,

    22                                      AVCodecID aCodecID)

    23   : mTaskQueue(aTaskQueue), mCodecID(aCodecID)

    24 {

    25   MOZ_COUNT_CTOR(FFmpegDataDecoder);

    26 }

    28 FFmpegDataDecoder::~FFmpegDataDecoder() {

    29   MOZ_COUNT_DTOR(FFmpegDataDecoder);

    30 }

    32 /**

    33  * FFmpeg calls back to this function with a list of pixel formats it supports.

    34  * We choose a pixel format that we support and return it.

    35  * For now, we just look for YUV420P as it is the only non-HW accelerated format

    36  * supported by FFmpeg's H264 decoder.

    37  */

    38 static PixelFormat

    39 ChoosePixelFormat(AVCodecContext* aCodecContext, const PixelFormat* aFormats)

    40 {

    41   FFMPEG_LOG("Choosing FFmpeg pixel format for video decoding.");

    42   for (; *aFormats > -1; aFormats++) {

    43     if (*aFormats == PIX_FMT_YUV420P) {

    44       FFMPEG_LOG("Requesting pixel format YUV420P.");

    45       return PIX_FMT_YUV420P;

    46     }

    47   }

    49   NS_WARNING("FFmpeg does not share any supported pixel formats.");

    50   return PIX_FMT_NONE;

    51 }

    53 nsresult

    54 FFmpegDataDecoder::Init()

    55 {

    56   FFMPEG_LOG("Initialising FFmpeg decoder.");

    58   if (!FFmpegRuntimeLinker::Link()) {

    59     NS_WARNING("Failed to link FFmpeg shared libraries.");

    60     return NS_ERROR_FAILURE;

    61   }

    63   if (!sFFmpegInitDone) {

    64     av_register_all();

    65 #ifdef DEBUG

    66     av_log_set_level(AV_LOG_DEBUG);

    67 #endif

    68     sFFmpegInitDone = true;

    69   }

    71   AVCodec* codec = avcodec_find_decoder(mCodecID);

    72   if (!codec) {

    73     NS_WARNING("Couldn't find ffmpeg decoder");

    74     return NS_ERROR_FAILURE;

    75   }

    77   if (avcodec_get_context_defaults3(&mCodecContext, codec) < 0) {

    78     NS_WARNING("Couldn't init ffmpeg context");

    79     return NS_ERROR_FAILURE;

    80   }

    82   mCodecContext.opaque = this;

    84   // FFmpeg takes this as a suggestion for what format to use for audio samples.

    85   mCodecContext.request_sample_fmt = AV_SAMPLE_FMT_FLT;

    87   // FFmpeg will call back to this to negotiate a video pixel format.

    88   mCodecContext.get_format = ChoosePixelFormat;

    90   AVDictionary* opts = nullptr;

    91   if (avcodec_open2(&mCodecContext, codec, &opts) < 0) {

    92     NS_WARNING("Couldn't initialise ffmpeg decoder");

    93     return NS_ERROR_FAILURE;

    94   }

    96   if (mCodecContext.codec_type == AVMEDIA_TYPE_AUDIO &&

    97       mCodecContext.sample_fmt != AV_SAMPLE_FMT_FLT &&

    98       mCodecContext.sample_fmt != AV_SAMPLE_FMT_FLTP) {

    99     NS_WARNING("FFmpeg AAC decoder outputs unsupported audio format.");

   100     return NS_ERROR_FAILURE;

   101   }

   103   FFMPEG_LOG("FFmpeg init successful.");

   104   return NS_OK;

   105 }

   107 nsresult

   108 FFmpegDataDecoder::Flush()

   109 {

   110   mTaskQueue->Flush();

   111   avcodec_flush_buffers(&mCodecContext);

   112   return NS_OK;

   113 }

   115 nsresult

   116 FFmpegDataDecoder::Shutdown()

   117 {

   118   if (sFFmpegInitDone) {

   119     avcodec_close(&mCodecContext);

   120   }

   121   return NS_OK;

   122 }

   124 } // namespace mozilla

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