Skip to content

Instantly share code, notes, and snippets.

@Lovesan
Created February 3, 2017 23:32
Show Gist options
  • Save Lovesan/64f04bf6fe3cf8ff3d39e357fa293698 to your computer and use it in GitHub Desktop.
Save Lovesan/64f04bf6fe3cf8ff3d39e357fa293698 to your computer and use it in GitHub Desktop.
FFmpeg & SDL2 - play audio & video
#define __STDC_CONSTANT_MACROS
#include <stdint.h>
#include <inttypes.h>
#include <windows.h>
#include <stdio.h>
extern "C"
{
#include <libavfilter/avfilter.h>
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
#include <libavdevice/avdevice.h>
#include <libavutil/imgutils.h>
#include <libswresample/swresample.h>
#include <libswscale/swscale.h>
#define SDL_MAIN_HANDLED
#include <SDL.h>
#include <SDL_thread.h>
#include <SDL_syswm.h>
#include <SDL_render.h>
#include <SDL_audio.h>
}
#define SDL_AUDIO_BUFFER_SIZE 1024;
typedef struct _PacketQueue
{
AVPacketList *first, *last;
int nb_packets, size;
CRITICAL_SECTION cs;
CONDITION_VARIABLE cv;
} PacketQueue;
int quit = 0;
PacketQueue audioq;
SwrContext *swrCtx;
void InitPacketQueue(PacketQueue * pq)
{
memset(pq, 0, sizeof(PacketQueue));
InitializeCriticalSection(&pq->cs);
InitializeConditionVariable(&pq->cv);
}
int PacketQueuePut(PacketQueue * pq, const AVPacket * srcPkt)
{
AVPacketList *elt;
AVPacket pkt;
int rv;
if (!pq) return -1;
rv = av_packet_ref(&pkt, srcPkt);
if (rv) return rv;
elt = (AVPacketList*)av_malloc(sizeof(AVPacketList));
if (!elt) return -1;
elt->pkt = pkt;
elt->next = NULL;
EnterCriticalSection(&pq->cs);
if (!pq->last)
pq->first = elt;
else
pq->last->next = elt;
pq->last = elt;
pq->nb_packets++;
pq->size += elt->pkt.size;
WakeConditionVariable(&pq->cv);
LeaveCriticalSection(&pq->cs);
return 0;
}
int PacketQueueGet(PacketQueue *pq, AVPacket *pkt, int block)
{
AVPacketList * elt;
int rv;
if (!pq || !pkt) return -1;
EnterCriticalSection(&pq->cs);
for (;;)
{
if (quit)
{
rv = -1;
break;
}
elt = pq->first;
if (elt)
{
pq->first = elt->next;
if (!pq->first)
pq->last = NULL;
pq->nb_packets--;
pq->size -= elt->pkt.size;
*pkt = elt->pkt;
av_free(elt);
rv = 1;
break;
}
else if (!block)
{
rv = 0;
break;
}
else
{
SleepConditionVariableCS(&pq->cv, &pq->cs, INFINITE);
}
}
LeaveCriticalSection(&pq->cs);
return rv;
}
int DecodeAudioFrame(AVCodecContext *ctx, uint8_t *audioBuf, int bufSize)
{
static AVPacket packet = { 0 };
static uint8_t* packetData = NULL;
static int packetSize = 0;
static AVFrame * frame = NULL;
static uint8_t converted_data[(192000 * 3) / 2];
static uint8_t * converted;
int len1, len2, dataSize = 0;
if (!frame)
{
frame = av_frame_alloc();
converted = &converted_data[0];
}
for (;;)
{
while (packetSize > 0) {
int gotFrame = 0;
len1 = avcodec_decode_audio4(ctx, frame, &gotFrame, &packet);
if (len1 < 0)
{
/* if error, skip frame */
packetSize = 0;
break;
}
packetData += len1;
packetSize -= len1;
if (gotFrame)
{
dataSize = av_samples_get_buffer_size(NULL, ctx->channels, frame->nb_samples, ctx->sample_fmt, 1);
int outSize = av_samples_get_buffer_size(NULL, ctx->channels, frame->nb_samples, AV_SAMPLE_FMT_FLT, 1);
len2 = swr_convert(swrCtx, &converted, frame->nb_samples, (const uint8_t**)&frame->data[0], frame->nb_samples);
memcpy(audioBuf, converted_data, outSize);
dataSize = outSize;
}
if (dataSize <= 0) {
/* No data yet, get more frames */
continue;
}
/* We have data, return it and come back for more later */
return dataSize;
}
if (packet.data)
{
//av_free_packet(&packet);
}
if (quit)
return -1;
if (PacketQueueGet(&audioq, &packet, 1) < 0)
return -1;
packetData = packet.data;
packetSize = packet.size;
}
return -1;
}
void AudioCallback(void *userdata, uint8_t * stream, int len)
{
AVCodecContext * ctx = (AVCodecContext*)userdata;
int len1, audioSize;
static uint8_t audioBuf[(192000 * 3) / 2];
static unsigned int audioBufSize = 0;
static unsigned int audioBufIndex = 0;
while (len > 0)
{
if (audioBufIndex >= audioBufSize)
{
// already sent all data; get more
audioSize = DecodeAudioFrame(ctx, audioBuf, sizeof(audioBuf));
if (audioSize < 0)
{
// error
audioBufSize = SDL_AUDIO_BUFFER_SIZE;
memset(audioBuf, 0, sizeof(audioBuf));
}
else
{
audioBufSize = audioSize;
}
audioBufIndex = 0;
}
len1 = audioBufSize - audioBufIndex;
if (len1 > len)
len1 = len;
memcpy(stream, (uint8_t *)audioBuf + audioBufIndex, len1);
len -= len1;
stream += len1;
audioBufIndex += len1;
}
}
int main()
{
int rv = 0;
AVFormatContext * ictx = NULL, *octx = NULL;
AVOutputFormat * ofmt = NULL;
AVInputFormat * ifmt = NULL;
SwsContext *swsCtx = NULL;
SDL_Window * window = NULL;
SDL_Renderer * renderer = NULL;
SDL_Texture * texture = NULL;
SDL_AudioSpec wantedSpec = { 0 }, audioSpec = { 0 };
char* filename = "file:video.mp4";
char err[1024];
av_register_all();
avcodec_register_all();
avdevice_register_all();
avformat_network_init();
rv = avformat_open_input(&ictx, filename, NULL, NULL);
if (rv) goto cleanup;
rv = avformat_find_stream_info(ictx, NULL);
if (rv) goto cleanup;
int audioStream = -1, videoStream = -1;
for (unsigned int s = 0; s < ictx->nb_streams; ++s)
{
av_dump_format(ictx, s, filename, FALSE);
if (ictx->streams[s]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO && audioStream < 0)
{
audioStream = s;
}
else if (ictx->streams[s]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && videoStream < 0)
{
videoStream = s;
}
}
if (audioStream < 0 && videoStream < 0) goto cleanup;
AVCodec *audioCodec = NULL, *videoCodec = NULL;
AVCodecContext *audioCtx = NULL, *videoCtx = NULL;
if (audioStream >= 0)
{
audioCodec = avcodec_find_decoder(ictx->streams[audioStream]->codecpar->codec_id);
if (!audioCodec)
goto cleanup;
audioCtx = avcodec_alloc_context3(audioCodec);
if (!audioCtx) goto cleanup;
rv = avcodec_parameters_to_context(audioCtx, ictx->streams[audioStream]->codecpar);
if (rv) goto cleanup;
rv = avcodec_open2(audioCtx, audioCodec, NULL);
if (rv) goto cleanup;
swrCtx = swr_alloc();
if (!swrCtx) goto cleanup;
av_opt_set_channel_layout(swrCtx, "in_channel_layout", audioCtx->channel_layout, 0);
av_opt_set_channel_layout(swrCtx, "out_channel_layout", audioCtx->channel_layout, 0);
av_opt_set_int(swrCtx, "in_sample_rate", audioCtx->sample_rate, 0);
av_opt_set_int(swrCtx, "out_sample_rate", audioCtx->sample_rate, 0);
av_opt_set_sample_fmt(swrCtx, "in_sample_fmt", audioCtx->sample_fmt, 0);
av_opt_set_sample_fmt(swrCtx, "out_sample_fmt", AV_SAMPLE_FMT_FLT, 0);
rv = swr_init(swrCtx);
if (rv) goto cleanup;
}
if (videoStream >= 0)
{
videoCodec = avcodec_find_decoder(ictx->streams[videoStream]->codecpar->codec_id);
if (!videoCodec)
goto cleanup;
videoCtx = avcodec_alloc_context3(videoCodec);
if (!videoCtx) goto cleanup;
rv = avcodec_parameters_to_context(videoCtx, ictx->streams[videoStream]->codecpar);
if (rv) goto cleanup;
rv = avcodec_open2(videoCtx, videoCodec, NULL);
if (rv) goto cleanup;
swsCtx = sws_getContext(videoCtx->width,
videoCtx->height,
videoCtx->pix_fmt,
videoCtx->width,
videoCtx->height,
AV_PIX_FMT_RGB24,
SWS_BILINEAR,
NULL,
NULL,
NULL);
if (!swsCtx) goto cleanup;
}
if (SDL_Init(SDL_INIT_AUDIO | SDL_INIT_VIDEO | SDL_INIT_TIMER))
{
fprintf(stderr, "Unable to init SDL: %s \n", SDL_GetError());
goto cleanup;
}
if (audioCodec)
{
InitPacketQueue(&audioq);
wantedSpec.channels = audioCtx->channels;
wantedSpec.freq = audioCtx->sample_rate;
wantedSpec.format = AUDIO_F32;
wantedSpec.silence = 0;
wantedSpec.samples = SDL_AUDIO_BUFFER_SIZE;
wantedSpec.userdata = audioCtx;
wantedSpec.callback = AudioCallback;
if (SDL_OpenAudio(&wantedSpec, &audioSpec) < 0) {
fprintf(stderr, "SDL_OpenAudio: %s\n", SDL_GetError());
goto cleanup;
}
SDL_PauseAudio(0);
}
AVFrame *pFrame = NULL, *pFrameRGB = NULL;
uint8_t *frameBuffer = NULL;
int numBytes, width, height;
if (videoCodec)
{
width = ictx->streams[videoStream]->codecpar->width;
height = ictx->streams[videoStream]->codecpar->height;
pFrame = av_frame_alloc();
if (!pFrame) goto cleanup;
pFrameRGB = av_frame_alloc();
if (!pFrameRGB) goto cleanup;
numBytes = av_image_get_buffer_size(AV_PIX_FMT_RGB24, width, height, 8);
if (numBytes < 1)
{
rv = numBytes;
goto cleanup;
}
frameBuffer = (uint8_t*)av_malloc(numBytes);
if (!frameBuffer) goto cleanup;
rv = av_image_fill_arrays(&pFrameRGB->data[0], &pFrameRGB->linesize[0], frameBuffer, AV_PIX_FMT_RGB24, width, height, 1);
if (rv < 0) goto cleanup;
window = SDL_CreateWindow(filename,
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
videoCtx->width,
videoCtx->height,
0);
renderer = SDL_CreateRenderer(window, -1, 0);
if (!renderer) goto cleanup;
texture = SDL_CreateTexture(
renderer,
SDL_PIXELFORMAT_RGB24,
SDL_TEXTUREACCESS_STREAMING,
videoCtx->width,
videoCtx->height);
if (!texture) goto cleanup;
}
AVPacket packet;
SDL_Event evt;
int iVideo = 0, iAudio = 0;
while (av_read_frame(ictx, &packet) >= 0)
{
if (packet.stream_index == videoStream)
{
rv = avcodec_send_packet(videoCtx, &packet);
if (rv) goto cleanup;
while (!avcodec_receive_frame(videoCtx, pFrame))
{
sws_scale(swsCtx,
pFrame->data,
pFrame->linesize,
0,
videoCtx->height,
pFrameRGB->data,
pFrameRGB->linesize);
SDL_UpdateTexture(texture, NULL, pFrameRGB->data[0], pFrameRGB->linesize[0]);
SDL_RenderClear(renderer);
SDL_RenderCopy(renderer, texture, NULL, NULL);
SDL_RenderPresent(renderer);
++iVideo;
}
}
else if (packet.stream_index == audioStream)
{
PacketQueuePut(&audioq, &packet);
}
av_packet_unref(&packet);
SDL_PollEvent(&evt);
switch (evt.type)
{
case SDL_QUIT:
quit = 1;
goto cleanup;
break;
default:
break;
}
}
cleanup:
WakeConditionVariable(&audioq.cv);
quit = 1;
if (rv)
{
av_strerror(rv, err, sizeof(err));
fprintf(stderr, "ERROR: %s\n", err);
}
if (frameBuffer)
av_free(frameBuffer);
if (pFrame)
av_frame_free(&pFrame);
if (pFrameRGB)
av_frame_free(&pFrameRGB);
if (videoCtx)
avcodec_close(videoCtx);
if (audioCtx)
avcodec_close(audioCtx);
if (swsCtx)
sws_freeContext(swsCtx);
if (swrCtx)
swr_free(&swrCtx);
if (texture)
SDL_DestroyTexture(texture);
if (renderer)
SDL_DestroyRenderer(renderer);
if (window)
SDL_DestroyWindow(window);
if (ictx)
avformat_close_input(&ictx);
if (octx)
avformat_free_context(octx);
avformat_network_deinit();
SDL_Quit();
return rv;
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment