SCM make_ffmpeg_input(SCM scm_file_name, SCM scm_debug)
{
SCM retval;
struct ffmpeg_t *self;
scm_dynwind_begin(0);
const char *file_name = scm_to_locale_string(scm_file_name);
scm_dynwind_free(file_name);
self = (struct ffmpeg_t *)scm_gc_calloc(sizeof(struct ffmpeg_t), "ffmpeg");
self->video_stream_idx = -1;
self->audio_stream_idx = -1;
SCM_NEWSMOB(retval, ffmpeg_tag, self);
int err;
err = avformat_open_input(&self->fmt_ctx, file_name, NULL, NULL);
if (err < 0) {
ffmpeg_destroy(retval);
scm_misc_error("make-ffmpeg-input", "Error opening file '~a': ~a", scm_list_2(scm_file_name, get_error_text(err)));
};
err = avformat_find_stream_info(self->fmt_ctx, NULL);
if (err < 0) {
ffmpeg_destroy(retval);
scm_misc_error("make-ffmpeg-input", "No stream information in file '~a': ~a", scm_list_2(scm_file_name, get_error_text(err)));
};
// TODO: only open desired streams
// Open video stream
self->video_stream_idx = av_find_best_stream(self->fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);
if (self->video_stream_idx >= 0)
self->video_codec_ctx = open_decoder(retval, scm_file_name, video_stream(self), "video");
// Open audio stream
self->audio_stream_idx = av_find_best_stream(self->fmt_ctx, AVMEDIA_TYPE_AUDIO, -1, -1, NULL, 0);
if (self->audio_stream_idx >= 0)
self->audio_codec_ctx = open_decoder(retval, scm_file_name, audio_stream(self), "audio");
// Print debug information
if (scm_is_true(scm_debug)) av_dump_format(self->fmt_ctx, 0, file_name, 0);
// Allocate input frames
self->video_target_frame = allocate_frame(retval);
self->audio_target_frame = allocate_frame(retval);
// Initialise data packet
av_init_packet(&self->pkt);
self->pkt.data = NULL;
self->pkt.size = 0;
scm_dynwind_end();
return retval;
}
/* ---------------------------------------------------------------------------- *
* menu() *
* ---------------------------------------------------------------------------- *
* Presented at system startup. Allows the user to select between three
* options by pressing certain keys on the keyboard:
* 's' - Audio loopback streaming
* 'n' - Tonal noise is generated by an NCO and added to the audio
* being captured from the audio codec.
* 'f' - The audio + tonal noise is passed to an adaptive LMS noise
* cancellation filter which will use the tonal noise estimate
* to remove the noise from the audio.
*
* This menu is shown upon exiting from any of the above options.
* ---------------------------------------------------------------------------- */
void menu(){
u8 inp = 0x00;
u32 CntrlRegister;
/* Turn off all LEDs */
Xil_Out32(LED_BASE, 0);
CntrlRegister = XUartPs_ReadReg(UART_BASEADDR, XUARTPS_CR_OFFSET);
XUartPs_WriteReg(UART_BASEADDR, XUARTPS_CR_OFFSET,
((CntrlRegister & ~XUARTPS_CR_EN_DIS_MASK) |
XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN));
xil_printf("\r\n\r\n");
xil_printf("Embedded LMS Filtering Demo\r\n");
xil_printf("Enter 's' to stream pure audio, 'n' to add tonal noise and 'f' to adaptively filter\r\n");
xil_printf("----------------------------------------\r\n");
// Wait for input from UART via the terminal
while (!XUartPs_IsReceiveData(UART_BASEADDR));
inp = XUartPs_ReadReg(UART_BASEADDR, XUARTPS_FIFO_OFFSET);
// Select function based on UART input
switch(inp){
case 's':
xil_printf("STREAMING AUDIO\r\n");
xil_printf("Press 'q' to return to the main menu\r\n");
audio_stream();
break;
case 'n':
xil_printf("ENTERING NOISE GENERATION OPERATION\r\n");
xil_printf("Select step size via the DIP switches...\r\n\n");
xil_printf("Press 'q' to return to the main menu\r\n");
tonal_noise();
break;
case 'f':
xil_printf("ENTERING LMS FILTERING OPERATION\r\n");
xil_printf("Press 'q' to return to the main menu\r\n");
lms_filter();
break;
default:
menu();
break;
} // switch
} // menu()
static int encode_audio(struct ffmpeg_t *self, AVFrame *audio_frame)
{
AVCodecContext *codec = audio_codec_ctx(self);
// Initialise data packet
AVPacket pkt = { 0 };
av_init_packet(&pkt);
// Encode the audio frame
int got_packet;
int err = avcodec_encode_audio2(codec, &pkt, audio_frame, &got_packet);
if (err < 0)
scm_misc_error("encode-audio", "Error encoding audio frame: ~a",
scm_list_1(get_error_text(err)));
// Write any new audio packets
if (got_packet)
write_frame(self, &pkt, codec, audio_stream(self), self->audio_stream_idx);
return got_packet;
}
static SCM list_timestamped_audio(struct ffmpeg_t *self, AVFrame *frame)
{
return scm_list_2(scm_from_locale_symbol("audio"),
scm_product(scm_from_int(frame_timestamp(frame)), time_base(audio_stream(self))));
}
