diff options
Diffstat (limited to 'ffmpeg-player')
| -rw-r--r-- | ffmpeg-player/CMakeLists.txt | 9 | ||||
| -rw-r--r-- | ffmpeg-player/main.c | 323 |
2 files changed, 332 insertions, 0 deletions
diff --git a/ffmpeg-player/CMakeLists.txt b/ffmpeg-player/CMakeLists.txt new file mode 100644 index 0000000..96daeb4 --- /dev/null +++ b/ffmpeg-player/CMakeLists.txt @@ -0,0 +1,9 @@ +cmake_minimum_required(VERSION 3.15 FATAL_ERROR) +project(ffmpeg-player C) + +set(DEMO_NEEDS_FFMPEG TRUE) +set(DEMO_NEEDS_SDL3 TRUE) +include("${CMAKE_CURRENT_LIST_DIR}/../common/c_cpp/CMakeLists.txt") + +add_executable(ffmpeg-player main.c) +target_link_libraries(ffmpeg-player PRIVATE common)
\ No newline at end of file diff --git a/ffmpeg-player/main.c b/ffmpeg-player/main.c new file mode 100644 index 0000000..8d0cea3 --- /dev/null +++ b/ffmpeg-player/main.c @@ -0,0 +1,323 @@ +// Barebones FFmpeg + SDL3 video playback +// +// SPDX-License-Identifier: GPL-3.0 +// +// - Assumes video and audio streams are both present +// - Assumes both streams start at 0 +// +// ref: https://github.com/libsdl-org/SDL/blob/main/test/testffmpeg.c +// ref: https://code.ffmpeg.org/FFmpeg/FFmpeg/src/branch/master/doc/examples/demux_decode.c +// +// Changelog: +// - 9/17/25: Initial release +// - 9/18/25: libswscale, flush decoders +// + +#include <libavcodec/avcodec.h> +#include <libavformat/avformat.h> +#include <libavutil/pixdesc.h> +#include <libswresample/swresample.h> +#include <libswscale/swscale.h> + +#include <SDL3/SDL.h> +#include <SDL3/SDL_main.h> + +typedef struct Decoder Decoder; +struct Decoder +{ + const AVStream* stream; + const AVCodecParameters* cpar; + const AVCodec* codec; + AVCodecContext* cctx; +}; + +static bool create_decoder(Decoder* dec, AVFormatContext* avfc, enum AVMediaType type) +{ + int ret = 0; + + if ((ret = av_find_best_stream(avfc, type, -1, -1, NULL, 0)) < 0) { + fprintf(stderr, "Failed to find stream: %s\n", av_err2str(ret)); + return false; + } + + dec->stream = avfc->streams[ret]; + dec->cpar = dec->stream->codecpar; + + if (!(dec->codec = avcodec_find_decoder(dec->stream->codecpar->codec_id))) { + fprintf(stderr, "Failed to open decoder\n"); + return false; + } + + if (!(dec->cctx = avcodec_alloc_context3(dec->codec))) { + fprintf(stderr, "Failed to allocate decoder context\n"); + return false; + } + + if ((ret = avcodec_parameters_to_context(dec->cctx, dec->stream->codecpar)) < 0) { + fprintf(stderr, "Failed to set decoder parameters: %s\n", av_err2str(ret)); + return false; + } + + if ((ret = avcodec_open2(dec->cctx, dec->codec, NULL)) < 0) { + fprintf(stderr, "Failed to open decoder: %s\n", av_err2str(ret)); + return false; + } + + return true; +} + +int main(int argc, char* argv[]) +{ + if (argc <= 1) { + fprintf(stderr, "Usage: %s <file>\n", argv[0]); + return EXIT_FAILURE; + } + + if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_EVENTS)) { + fprintf(stderr, "Failed to initialize SDL: %s\n", SDL_GetError()); + return EXIT_FAILURE; + } + + int ret = 0; + + av_log_set_level(AV_LOG_VERBOSE); + + AVFormatContext* avfc = NULL; + if ((ret = avformat_open_input(&avfc, argv[1], NULL, NULL)) < 0) { + fprintf(stderr, "Failed to open input: %s\n", av_err2str(ret)); + return EXIT_FAILURE; + } + + if ((ret = avformat_find_stream_info(avfc, NULL)) < 0) { + fprintf(stderr, "Failed to find stream info: %s\n", av_err2str(ret)); + return EXIT_FAILURE; + } + + Decoder vdec = { 0 }; + if (!create_decoder(&vdec, avfc, AVMEDIA_TYPE_VIDEO)) { + return EXIT_FAILURE; + } + + Decoder adec = { 0 }; + if (!create_decoder(&adec, avfc, AVMEDIA_TYPE_AUDIO)) { + return EXIT_FAILURE; + } + + SDL_Window* wnd = SDL_CreateWindow("ffmpeg-player", vdec.cpar->width, vdec.cpar->height, SDL_WINDOW_HIDDEN); + if (!wnd) { + fprintf(stderr, "Failed to create window: %s\n", SDL_GetError()); + return EXIT_FAILURE; + } + + int ww = vdec.cpar->width; + int wh = vdec.cpar->height; + SDL_Rect drect; + if (SDL_GetDisplayBounds(SDL_GetDisplayForWindow(wnd), &drect)) { + while (ww >= drect.w || wh >= drect.h) { + ww /= 2; + wh /= 2; + } + } + SDL_SetWindowSize(wnd, ww, wh); + SDL_ShowWindow(wnd); + + SDL_Renderer* rnd = SDL_CreateRenderer(wnd, NULL); + if (!rnd) { + fprintf(stderr, "Failed to create renderer: %s\n", SDL_GetError()); + return EXIT_FAILURE; + } + + SDL_SetRenderVSync(rnd, 1); + + AVPacket* avp = av_packet_alloc(); + AVFrame* avf = av_frame_alloc(); + AVFrame* avf_sdl = av_frame_alloc(); + SDL_assert(avp && avf && avf_sdl); + + // Use a YUV texture when blitting to the screen. Most video files are decoded to + // AV_PIX_FMT_YUV420P frames anyway, but convert anyway to use the same code path. + SDL_Texture* tex = SDL_CreateTexture(rnd, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, + vdec.cpar->width, vdec.cpar->height); + if (!tex) { + fprintf(stderr, "Failed to create texture: %s\n", SDL_GetError()); + return EXIT_FAILURE; + } + + avf_sdl->format = AV_PIX_FMT_YUV420P; + avf_sdl->width = vdec.cpar->width; + avf_sdl->height = vdec.cpar->height; + if ((ret = av_frame_get_buffer(avf_sdl, 32)) < 0) { + fprintf(stderr, "Failed to allocate frame: %s\n", av_err2str(ret)); + return EXIT_FAILURE; + } + if ((ret = av_frame_make_writable(avf_sdl)) < 0) { + fprintf(stderr, "Failed to make frame writable: %s\n", av_err2str(ret)); + return EXIT_FAILURE; + } + + struct SwsContext* sws = sws_getContext(vdec.cpar->width, vdec.cpar->height, vdec.cpar->format, + vdec.cpar->width, vdec.cpar->height, AV_PIX_FMT_YUV420P, + 0, NULL, NULL, NULL); + if (!sws) { + fprintf(stderr, "Failed to create libswscale context\n"); + return EXIT_FAILURE; + } + + // libswresample is like libswscale but for audio. This barely works because I don't + // really understand audio programming. + SDL_AudioSpec aspec = { 0 }; + aspec.format = SDL_AUDIO_F32; + aspec.channels = adec.cctx->ch_layout.nb_channels; + aspec.freq = adec.cctx->sample_rate; + SDL_AudioStream* astream = SDL_OpenAudioDeviceStream(SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &aspec, NULL, NULL); + if (!astream) { + fprintf(stderr, "Failed to create audio device stream: %s\n", SDL_GetError()); + return EXIT_FAILURE; + } + SDL_ResumeAudioDevice(SDL_GetAudioStreamDevice(astream)); + + SwrContext* swr = swr_alloc(); SDL_assert(swr); + ret = swr_alloc_set_opts2(&swr, + &adec.cctx->ch_layout, AV_SAMPLE_FMT_FLT, adec.cctx->sample_rate, + &adec.cctx->ch_layout, adec.cctx->sample_fmt, adec.cctx->sample_rate, + 0, NULL); + if (ret < 0) { + fprintf(stderr, "Failed to set swresample parameters: %s\n", av_err2str(ret)); + return EXIT_FAILURE; + } + if ((ret = swr_init(swr)) < 0) { + fprintf(stderr, "Failed to initialize swresample: %s\n", av_err2str(ret)); + return EXIT_FAILURE; + } + + bool eof = false; + bool flushed = false; + bool running = true; + while (running) { + SDL_Event evt; + while (SDL_PollEvent(&evt)) { + if (evt.type == SDL_EVENT_QUIT) { + running = false; + } + if (evt.type == SDL_EVENT_KEY_DOWN) { + if (evt.key.key == SDLK_ESCAPE || evt.key.key == SDLK_Q) { + running = false; + } + } + } + + // Read a packet from the file + if (!eof) { + ret = av_read_frame(avfc, avp); + if (ret < 0) { + if (ret == AVERROR_EOF) { + eof = true; + } else { + fprintf(stderr, "Error reading frame: %s\n", av_err2str(ret)); + return EXIT_FAILURE; + } + } + + if (eof) { + if (!flushed) { + // Send NULL to flush the decoders + avcodec_send_packet(vdec.cctx, NULL); + avcodec_send_packet(adec.cctx, NULL); + flushed = true; + } + // End of file, no need to continue feeding the decoders + continue; + } + + // Send encoded packet to decoder. + // Decoding isn't a 1:1 process. One or more packets produce one or more frames. + if (avp->stream_index == vdec.stream->index) { + if ((ret = avcodec_send_packet(vdec.cctx, avp)) < 0) { + fprintf(stderr, "Failed to send video packet to decoder: %s\n", av_err2str(ret)); + return EXIT_FAILURE; + } + } + if (avp->stream_index == adec.stream->index) { + if ((ret = avcodec_send_packet(adec.cctx, avp)) < 0) { + fprintf(stderr, "Failed to send audio packet to decoder: %s\n", av_err2str(ret)); + return EXIT_FAILURE; + } + } + + av_packet_unref(avp); + } + + static double start = -1.0f; + if (start < 0.0f) { + start = SDL_GetTicks() / 1e3f; + } + + // debug + static double d_vpts = 0.0f; + static double d_apts = 0.0f; + + // Receive zero or more video frames from the video decoder + while (avcodec_receive_frame(vdec.cctx, avf) >= 0) { + // This sync really sucks. I might fix it some day. + const double now = SDL_GetTicks() / 1e3f; + const double pts = avf->best_effort_timestamp * av_q2d(vdec.stream->time_base); + d_vpts = pts; + if (now - start < pts) { + SDL_DelayPrecise((pts - now + start) * SDL_NS_PER_SECOND); + } + + sws_scale(sws, (const uint8_t* const*)avf->data, avf->linesize, 0, avf->height, + avf_sdl->data, avf_sdl->linesize); + + bool updated = SDL_UpdateYUVTexture(tex, NULL, avf_sdl->data[0], avf_sdl->linesize[0], + avf_sdl->data[1], avf_sdl->linesize[1], + avf_sdl->data[2], avf_sdl->linesize[2]); + if (!updated) { + fprintf(stderr, "Failed to update YUV texture: %s\n", SDL_GetError()); + return EXIT_FAILURE; + } + + SDL_SetRenderDrawColor(rnd, 0x00, 0x00, 0x00, 0xFF); + SDL_RenderClear(rnd); + SDL_SetRenderDrawColor(rnd, 0xFF, 0xFF, 0xFF, 0xFF); + SDL_RenderTexture(rnd, tex, NULL, NULL); + SDL_RenderDebugTextFormat(rnd, 10, 10, "now %.2f\n", now); + SDL_RenderDebugTextFormat(rnd, 10, 20, "v pts %.2f\n", d_vpts); + SDL_RenderDebugTextFormat(rnd, 10, 30, "a pts %.2f\n", d_apts); + + SDL_RenderPresent(rnd); + + av_frame_unref(avf); + } + + // Receive one or more audio frames from the audio decoder + while (avcodec_receive_frame(adec.cctx, avf) >= 0) { + d_apts = avf->best_effort_timestamp * av_q2d(adec.stream->time_base); + + int max_out = swr_get_out_samples(swr, avf->nb_samples); + if (max_out > 0) { + uint8_t* out_data = NULL; + int out_linesize = 0; + + av_samples_alloc(&out_data, &out_linesize, avf->ch_layout.nb_channels, + max_out, AV_SAMPLE_FMT_FLT, 0); + + const uint8_t** in = (const uint8_t**)avf->extended_data; + ret = swr_convert(swr, &out_data, max_out, in, avf->nb_samples); + if (ret > 0) { + size_t out_bytes = (size_t)ret * avf->ch_layout.nb_channels * + av_get_bytes_per_sample(AV_SAMPLE_FMT_FLT); + SDL_PutAudioStreamData(astream, out_data, out_bytes); + } + + av_freep(&out_data); + } + + av_frame_unref(avf); + } + } + + SDL_DestroyWindow(wnd); + + return EXIT_SUCCESS; +} |